WRKY transcription factors are involved in the regulation of response to biotic and abiotic stresses in plants. A full-length cDNA clone of rice WRKY82 gene (OsWRKY82) was isolated from a cDNA library generated from...WRKY transcription factors are involved in the regulation of response to biotic and abiotic stresses in plants. A full-length cDNA clone of rice WRKY82 gene (OsWRKY82) was isolated from a cDNA library generated from leaves infected by Magnaporthe grisea. OsWRKY82 contained an entire open reading frame in length of 1 701 bp, and was predicted to encode a polypeptide of 566 amino acid residues consisting of two WRKY domains, each with a zinc finger motif of C2H2, belonging to the WRKY subgroup I. OsWRKY82 shared high identity at the amino acid level with those from Sorghum bicolor, Hordeum vulgare, and Zea mays. The transcript level of OsWRKY82 was relatively higher in stems, leaves, and flowers, and less abundant in grains. It was induced by inoculation with M. grisea and Rhizoctonia solani. However, the inducible expression in incompatible rice-M. grisea interactions was earlier and greater than that in compatible interactions. The expression of OsWRKY82 was up-regulated by methyl jasmonate and ethephon, whereas salicylic acid exerted no effects on its expression. Moreover, OsWRKY82 exhibited transcriptional activation ability in yeast. Additionally, OsWRKY82 transcripts could be induced by wounding and heat shocking, but not by abscisic acid, cold, high salinity and dehydration. By contrast, gibberellin suppressed the expression of OsWRKY82. These indicate that OsWRKY82 is a multiply stress-inducible gene responding to both biotic and abiotic stresses, and may be involved in the regulation of defense response to pathogens and tolerance against abiotic stresses by jasmonic acid/ethylene-dependent signaling pathway.展开更多
Members of the Pathogenesis Related(PR)10 protein family have been identified in a variety of plant species and a wide range of functions ranging from defense to growth and development has been attributed to them.PR10...Members of the Pathogenesis Related(PR)10 protein family have been identified in a variety of plant species and a wide range of functions ranging from defense to growth and development has been attributed to them.PR10 protein possesses ribonuclease(RNase)activity,interacts with phytohormones,involved in hormone-mediated signalling,afforded protection against various phytopathogenic fungi,bacteria,and viruses particularly in response to biotic and abiotic stresses.The resistance mechanism of PR10 protein may include activation of defense signalling pathways through possible interacting proteins involved in mediating responses to pathogens,degradation of RNA of the invading pathogens.Moreover,several morphological changes have been shown to accompany the enhanced abiotic stress tolerance.In this review,the possible mechanism of action of PR10 protein against biotic and abiotic stress has been discussed.Furthermore,our findings also confirmed that the in vivo Nitric oxide(NO)is essential for most of environmental abiotic stresses and disease resistance against pathogen infection.The proper level of NO may be necessary and beneficial,not only in plant response to the environmental abiotic stress,but also to biotic stress.The updated information on this interesting group of proteins will be useful in future research to develop multiple stress tolerance in plants.展开更多
von Willebrand factor A(vWA)genes are well characterized in humans except for few BONZAI genes,but the vWA genes are least explored in plants.Considering the novelty and vital role of vWA genes,this study aimed at cha...von Willebrand factor A(vWA)genes are well characterized in humans except for few BONZAI genes,but the vWA genes are least explored in plants.Considering the novelty and vital role of vWA genes,this study aimed at characterization of vWA superfamily in rice.Rice genome was found to have 40 vWA genes distributed across all the 12 chromosomes,and 20 of the 40 vWA genes were unique while the remaining shared large fragment similarities with each other,indicating gene duplication.In addition to vWA domain,vWA proteins possess other different motifs or domains,such as ubiquitin interacting motif in protein degradation pathway,and RING finger in protein-protein interaction.Expression analysis of vWA genes in available expression data suggested that they probably function in biotic and abiotic stress responses including hormonal response and signaling.The frequency of transposon elements in the entire 3K rice germplasm was negligible except for 9 vWA genes,indicating the importance of these genes in rice.Structural and functional diversities showed that the vWA genes in a blast-resistant rice variety Tetep had huge variations compared to blast-susceptible rice varieties HP2216 and Nipponbare.qRT-PCR analysis of vWA genes in Magnaporthe oryzae infected rice tissues indicated OsvWA9,OsvWA36,OsvWA37 and OsvWA18 as the optimal candidate genes for disease resistance.This is the first attempt to characterize vWA gene family in plant species.展开更多
Plants are recurrently exposed to myriads of biotic and abiotic stresses leading to several biochemical and physiological variations that cause severe impacts on plant growth and survival.To overcome these challenges,...Plants are recurrently exposed to myriads of biotic and abiotic stresses leading to several biochemical and physiological variations that cause severe impacts on plant growth and survival.To overcome these challenges,plants activate two primary defense mechanisms,such as structural response(cell wall strengthening and waxy epidermal cuticle development)and metabolic changes,including the synthesis of anti-microbial compounds and proteins,especially the pathogenesis-related(PR)proteins.PR proteins are members of a super large family of defense proteins that exhibit antimicrobial activities.Their over-expression in plants provides tolerance to many abiotic and biotic stresses.PR proteins have been classified into 17 families,including PR-5–also called thaumatin-like proteins(TLPs)that involve osmotin and osmotin-like proteins(OLPs).Osmotin was first identified in tobacco(Nicotiana tabacum var.Wisconsin 38),and then its homolog proteins(OLPs)were reported from the whole plant kingdom.Osmotin and OLPs are ubiquitous in all fruits and vegetables.Their expression has been detected in various plant tissues and organs.The phylogenetic tree studies revealed that the osmotin group originated from spermatophytes.Moreover,the atomic structure of OLP has shown similarity to thaumatin and TLPs from monocot and eudicot species,which determines a strong evolutionary pressure in flowering plants for conserving thaumatin fold.This is associated with the role of these proteins against pathogens as defense molecules and to induce stress tolerance to plants against several biotic and abiotic factors.In this review,we have briefly described the development history of osmotin,including its function and mechanism to induce biotic and abiotic stress tolerance to plants.展开更多
Plant calcineurin B-like (CBL) proteins have been proposed as important Ca2+ sensors and specifically interact with CBL-interacting protein kinases (CIPKs) in plant-specific calcium signaling. Here, we identified...Plant calcineurin B-like (CBL) proteins have been proposed as important Ca2+ sensors and specifically interact with CBL-interacting protein kinases (CIPKs) in plant-specific calcium signaling. Here, we identified and isolated 15 CIPK genes in a japonica rice variety Nipponbare based on the predicted sequences of rice CIPK gene family. Gene structure analysis showed that these 15 genes were divided into intron-less and intron-rich groups, and OsCIPK3 and OsCIPK24 exhibited alternative splicing in their mature process. The phylogenetic analyses indicated that rice CIPKs shared an ancestor with Arabidopsis and poplar CIPKs. Analyses of gene expression showed that these OsCIPK genes were differentially induced by biotic stresses such as bacterial blight and abiotic stresses (heavy metal such as Hg2+, high salinity, cold and ABA). Interestingly, five OsCIPK genes, OsCIPK1, 2, 10, 11 and 12, were transcriptionally up-regulated after bacterial blight infection whereas four OsCIPK genes, OsCIPK2, 10, 11 and 14, were induced by all treatments, indicating that some of OsCIPK genes are involved in multiple stress response pathways in plants. Our finding suggests that CIPKs play a key role in both biotic and abiotic stress responses.展开更多
Stresses are defined as a variety of environmental factors that pose adverse impacts on plant growth and survival. Rice is an important food crop, whose quality and yield may be affected by environmental stresses. Mic...Stresses are defined as a variety of environmental factors that pose adverse impacts on plant growth and survival. Rice is an important food crop, whose quality and yield may be affected by environmental stresses. MicroRNAs play an important role in response to stresses, which regulate gene expression at the post-transcription level by cleaving target mRNAs and inhibiting mRNA translation. This paper summarized the mechanism of action of miRNAs and introduced research progress of miRNAs in rice under biotic and abiotic stresses, which provided reference for revealing the functional role of rice miRNAs in stress resistance.展开更多
The “quasi-essential element” silicon (Si) is not considered indispensable for plant growth and its accumulation varies between species largely due to differential uptake phenomena. Silicon uptake and distribution i...The “quasi-essential element” silicon (Si) is not considered indispensable for plant growth and its accumulation varies between species largely due to differential uptake phenomena. Silicon uptake and distribution is a complex process involving the participation of three transporters (Lsi1, Lsi2 and Lsi6) and is beneficial during recovery from multiple stresses. This review focuses on the pivotal role of silicon in counteracting several biotic and abiotic stresses including nutrient imbalances, physical stresses together with uptake, transport of this metalloid in a wide variety of dicot and monocot species. The knowledge on the beneficial effects of silicon and possible Si-induced mechanisms of minimizing stress has been discussed. Accumulation of silicon beneath the cuticles fortifies the cell wall against pathogen attack. Si-induced reduction of heavy metal uptake, root-shoot translocation, chelation, complexation, upregulation of antioxidative defense responses and regulation of gene expression are the mechanisms involved in alleviation of heavy metal toxicity in plants. Silicon further improves growth and physiological attributes under salt and drought stress. Effective use of silicon in agronomy can be an alternative to the prevalent practice of traditional fertilizers for maintaining sustainable productivity. Therefore, soil nutrition with fertilizers containing plant-available silicon may be considered a cost-effective way to shield plant from various stresses, improve plant growth as well as yield and attain sustainable cultivation worldwide.展开更多
This unique study evaluates the effects of Ralstonia solanacearum (Rs) induced biotic stress in two cultivars, Zingiber officinale (ginger) and Lycopersicon esculentum (tomato). They were grown in pots and hydroponic ...This unique study evaluates the effects of Ralstonia solanacearum (Rs) induced biotic stress in two cultivars, Zingiber officinale (ginger) and Lycopersicon esculentum (tomato). They were grown in pots and hydroponic systems with controls;to induce biotic stress, about 8 × 104 colony forming units of Rs suspension was injected into the healthy test plants. Upon induction of Rs stress, highly significant (p 0.01) biochemical changes (%) were noticed in respect to controls: carbohydrate content was generally high in both plants;while they showed decreased starch and protein contents;phenolics showed a swing of decrease or increase between pot and hydroponic systems;and all plants in general showed higher (3-6 fold) proline content upon induction of biotic stress. Regarding oxidative stress isozymes (OSE), superoxide dismutase (EC 1.15.1.1) isozymes were normally 3, but treated hydroponics had 4 with comparable relative mobility values;peroxidase (EC 1.11.1.7) isozymes were generally 2, except for treated hydroponic tomato. Briefly, Rs induced biotic stress caused wilt symptoms in ginger, but did not affect tomato though its biochemical and OSE patterns especially in those grown as hydroponics were elicited to significantly higher levels.展开更多
Biotic and abiotic stresses are major limiting factors for high crop productivity worldwide. A landrace collection consisting of 380 durum wheat(Triticum turgidum L. var. durum) entries originating in several countrie...Biotic and abiotic stresses are major limiting factors for high crop productivity worldwide. A landrace collection consisting of 380 durum wheat(Triticum turgidum L. var. durum) entries originating in several countries along with four check varieties were evaluated for biotic stresses:yellow rust(Puccinia striiformis Westendorf f. sp. tritici) and wheat stem sawfly(WSS) Cephus cinctus Norton(Hymenoptera: Cephidae), and abiotic stresses: cold and drought. The main objectives were to(i) quantify phenotypic diversity and identify variation in the durum wheat landraces for the different stresses and(ii) characterize the agronomic profiles of landraces in reaction to the stresses. Significant changes in reactions of landraces to stresses were observed.Landraces resistant to each stress were identified and agronomically characterized.Percentage reduction due to the stresses varied from 11.4%(yellow rust) to 21.6%(cold stress) for 1000-kernel weight(TKW) and from 19.9(yellow rust) to 91.9%(cold stress) for grain yield. Landraces from Asia and Europe showed enhanced genetic potential for both grain yield and cold tolerance under highland rainfed conditions of Iran. The findings showed that TKW and yield productivity could be used to assess the response of durum wheat landraces to different stresses. In conclusion, landraces showed high levels of resistance to both biotic and abiotic stresses, and selected landraces can serve in durum wheat breeding for adaptation to cold and drought-prone environments.展开更多
The late Maastrichtian witnessed substantial surges in Deccan volcanism,prompting the hypothesis that these voluminous pulses may have instigated repeated episodes of ocean acidification during this period.The Cretace...The late Maastrichtian witnessed substantial surges in Deccan volcanism,prompting the hypothesis that these voluminous pulses may have instigated repeated episodes of ocean acidification during this period.The Cretaceous-Palaeogene(K/Pg)boundary at Bidart(France)is preceded by a~0.5 m thick interval with geochemical and taphonomic vestiges of an ocean acidification event linked with Deccan volcanism.New planktic foraminifera census and morphometric data now confirm biotic stress conditions related to acidification in the Deccan benchmark interval.The absolute abundance data of larger(>150μm)heavily calcified planktic morphogroups show fluctuating populations throughout zone CF1(spanning the final~225 ky),lowest peaks within the Deccan benchmark,and a demographic collapse(>90%)at the K/Pg boundary.The analyzed species are generally reduced in size,with thinner test walls in this~0.5 m interval,indicating the likelihood of calcification stress as a contributor to the overall biotic stress.At the K/Pg boundary,maximum biotic stress is recorded in all the tested faunal proxies.A preliminary graphic correlation of zone CF1 at Bidart with the auxiliary GSSP at Elles(Tunisia)constrains the Deccan benchmark interval of high biotic stress to the final~58ky of the late Maastrichtian,culminating in the K/Pg mass extinction.The volcanogenic Hg peaks coincident with faunal and taphonomic evidence of ocean acidification strengthen the Deccan-related ocean acidification hypothesis.展开更多
The aroma of fragrant rice is one of the grain quality attributes that significantly influenceconsumer preferences and prices in world markets. The volatile compound 2-acetyl-1-pyrroline (2AP) isrecognized as a key co...The aroma of fragrant rice is one of the grain quality attributes that significantly influenceconsumer preferences and prices in world markets. The volatile compound 2-acetyl-1-pyrroline (2AP) isrecognized as a key component of the aroma in fragrant rice. The variation in grain 2AP content amongvarious fragrant rice varieties is associated with the expression of the badh2 gene, with 19 alleles havingbeen identified so far. The grain 2AP content is strongly influenced by environmental and managementfactors during cultivation as well as post-harvest conditions. This review pinpointed the major abiotic andbiotic factors that control grain 2AP content. Abiotic factors refer to water, temperature, light quality,fertilizer application (both macro- and micro-nutrients), and soil properties, including salinity, while bioticfactors include microorganisms that produce aromatic compounds, thus influencing the grain aroma infragrant rice. Post-harvest management, including storage and drying conditions, can significantly impactthe grain 2AP content, and proper post-harvest conditions can intensify the grain aroma. This reviewsuggests that there are rice varieties that can serve as potential sources of genetic material for breedingrice varieties with high grain aroma content. It offers an overview of recent research on the major factorsaffecting the aroma content in fragrant rice. This knowledge will facilitate further research on theproduction of high-quality rice to meet the demands of farmers and consumers.展开更多
Hydrogen sulfide (H2S) is an important gaseous molecule in various plant developmental processes and plant stress responses. In this study, the transgenic Arabidopsis thaliana plants with modulated expressions of tw...Hydrogen sulfide (H2S) is an important gaseous molecule in various plant developmental processes and plant stress responses. In this study, the transgenic Arabidopsis thaliana plants with modulated expressions of two cysteine desulfhydrases, and exogenous H2S donor (sodium hydrosulfide, NariS) and H2S scavenger (hypotaurine, HT) pre-treated plants were used to dissect the involvement of H2S in plant stress responses. The cysteine desulfhydrases overexpressing plants and NariS pre-treated plants exhibited higher endogenous H2S level and improved abiotic stress tolerance and biotic stress resistance, while cysteine desulfhydrases knockdown plants and HT pre-treated plants displayed lower endogenous H2S level and decreased stress resistance. Moreover, H2S upregulated the transcripts of multiple abiotic and biotic stress-related genes, and inhibited reactive oxygen species (ROS) accumulation. Interest- ingly, MlR393-mediated auxin signaling including MIR393a/b and their target genes (TIR1, AFB1, AFB2, and AFB3) was transcrip-tionally regulated by H2S, and was related with H2S-induced antibacterial resistance. Moreover, H2S regulated 50 carbon metabolites including amino acids, organic acids, sugars, sugar alcohols, and aromatic amines. Taken together, these results indicated that cysteine desulfhydrase and H2S conferred abiotic stress tolerance and biotic stress resistance, via affecting the stress-related gene expressions, ROS metabolism, metabolic homeostasis, and MIR393-targeted auxin receptors.展开更多
Agricultural production is hampered by disease,pests,and environmental stresses.To minimize yield loss,it is important to develop crop cultivars with resistance or tolerance to their respective biotic and abiotic cons...Agricultural production is hampered by disease,pests,and environmental stresses.To minimize yield loss,it is important to develop crop cultivars with resistance or tolerance to their respective biotic and abiotic constraints.Transformation techniques are not optimized for many species and desirable cultivars may not be amenable to genetic transformation,necessitating inferior cultivar usage and time-consuming introgression through backcrossing to the preferred variety.Overcoming these limitations will greatly facilitate the development of disease,insect,and abiotic stress tolerant crops.One such avenue for rapid crop improvement is the development of viral systems to deliver CRISPR/Cas-based genome editing technology to plants to generate targeted beneficial mutations.Viral delivery of genomic editing constructs can theoretically be applied to span the entire host range of the virus utilized,circumventing the challenges associated with traditional transformation and breeding techniques.Here we explore the types of viruses that have been optimized for CRISPR/Cas9 delivery,the phenotypic outcomes achieved in recent studies,and discuss the future potential of this rapidly advancing technology.展开更多
As sessile organisms,plants have to cope with environmental change and numerous biotic and abiotic stress.Upon perceiving environmental cues and stress signals using different types of receptors,plant cells initiate i...As sessile organisms,plants have to cope with environmental change and numerous biotic and abiotic stress.Upon perceiving environmental cues and stress signals using different types of receptors,plant cells initiate immediate and complicated signaling to regulate cellular processes and respond to stress.Receptor-like cytoplasmic kinases(RLCKs)transduce signals from receptors to cellular components and play roles in diverse biological processes.Recent studies have revealed the hubbing roles of RLCKs in plant responses to biotic stress.Emerging evidence indicates the important regulatory roles of RLCKs in plant responses to abiotic stress,growth,and development.As a pivot of cellular signaling,the activity and stability of RLCKs are dynamically and tightly controlled.Here,we summarize the current understanding of how RLCKs regulate plant responses to biotic and abiotic stress.展开更多
Lignin is a polymer of phenylpropanoid compounds formed through a complex biosynthesis route, represented by a metabolic grid for which most of the genes involved have been sequenced in several plants, mainly in the m...Lignin is a polymer of phenylpropanoid compounds formed through a complex biosynthesis route, represented by a metabolic grid for which most of the genes involved have been sequenced in several plants, mainly in the model-plants Arabidopsis thaliana and Populus. Plants are exposed to different stresses, which may change lignin content and composition. In many cases, particularly for plant-microbe interactions, this has been suggested as defence responses of plants to the stress. Thus, understanding how a stressor modulates expression of the genes related with lignin biosynthesis may allow us to develop study-models to increase our knowledge on the metabolic control of lignin deposition in the cell wall. This review focuses on recent literature reporting on the main types of abiotic and biotic stresses that alter the biosynthesis of lignin in plants.展开更多
Stomatal aperture controls the balance between transpirational water loss and photosynthetic carbon dioxide(CO2)uptake.Stomata are surrounded by pairs of guard cells that sense and transduce environmental or stress si...Stomatal aperture controls the balance between transpirational water loss and photosynthetic carbon dioxide(CO2)uptake.Stomata are surrounded by pairs of guard cells that sense and transduce environmental or stress signals to induce diverse endogenous responses for adaptation to environmental changes.In a recent decade,hydrogen sulfide(H2S)has been recognized as a signaling molecule that regulates stomatal movement.In this review,we summarize recent progress in research on the regulatory role of H2S in stomatal movement,including the dynamic regulation of phytohormones,ion homeostasis,and cell structural components.We focus especially on the cross talk among H2S,nitric oxide(NO),and hydrogen peroxide(H2O2)in guard cells,as well as on H2S-mediated post-translational protein modification(cysteine thiol persulfidation).Finally,we summarize the mechanisms by which H2S interacts with other signaling molecules in plants under abiotic or biotic stress.Based on evidence and clues from existing research,we propose some issues that need to be addressed in the future.展开更多
The agriculture sector is no exception to the widespread usage of deep learning tools and techniques.In this paper,an automated detection method on the basis of pre-trained Convolutional Neural Network(CNN)models is p...The agriculture sector is no exception to the widespread usage of deep learning tools and techniques.In this paper,an automated detection method on the basis of pre-trained Convolutional Neural Network(CNN)models is proposed to identify and classify paddy crop biotic stresses from the field images.The proposed work also provides the empirical comparison among the leading CNN models with transfer learning from the ImageNet weights namely,Inception-V3,VGG-16,ResNet-50,DenseNet-121 and MobileNet-28.Brown spot,hispa,and leaf blast,three of the most common and destructive paddy crop biotic stresses that occur during the flowering and ripening growth stages are considered for the experimentation.The experimental results reveal that the ResNet-50 model achieves the highest average paddy crop stress classification accuracy of 92.61%outperforming the other considered CNN models.The study explores the feasibility of CNN models for the paddy crop stress identification as well as the applicability of automated methods to non-experts.展开更多
Despite increasing knowledge of barnyardgrass(Echinochloa crus-galli) interference with rice, relatively little is known how endophytes improve the ability of rice against barnyardgrass stress. Here, we provided a det...Despite increasing knowledge of barnyardgrass(Echinochloa crus-galli) interference with rice, relatively little is known how endophytes improve the ability of rice against barnyardgrass stress. Here, we provided a detailed temporal characterization of rice root-associated microbiomes during co-cultivation with barnyardgrass and a comparison with the microbiomes of weed-free rice plants. Alpha diversity analysis indicated that barnyardgrass had the opposite effects on endophytic bacteria and fungi in rice roots, in terms of the community diversity, richness and coverage at the rice seedling stage. Principal coordinate analysis showed that barnyardgrass had only a minor effect on the community composition of endophytes in rice roots at the rice seedling stage, but showed a significant and maximum interference at the heading stage. Rice recruited many endophytes to resist biotic stress from barnyardgrass, especially for fungi. PICRUSt(phylogenetic investigation of communities by reconstruction of unobserved states) predictive analysis indicated that 23 metabolic pathways of bacteria were overrepresented in rice. In addition, the main trophic mode of fungi was pathotroph according to FUNGuild analysis. A positive correlation between bacteria and fungi in rice roots was found via network analysis. Anaeromyxobacter, Azospira and Pseudolabrys were the vital bacteria, Phaeosphaeria and Funneliformis were the dominant fungi in maintaining the stability of the ecological network. These results provided data and a theoretical basis for the in-depth understanding of what role endophytes play in rice resistance to barnyardgrass stress and will have implications on improving the resistance of rice against biotic stress using root microbiota.展开更多
As superficial structures,non-glandular trichomes,protect plant organs against multiple biotic and abiotic stresses.The protective and defensive roles of these epidermal appendages are crucial to developing organs and...As superficial structures,non-glandular trichomes,protect plant organs against multiple biotic and abiotic stresses.The protective and defensive roles of these epidermal appendages are crucial to developing organs and can be attributed to the excellent combination of suitable structural traits and chemical reinforcement in the form of phenolic compounds,primarily fl avonoids.Both the formation of trichomes and the accumulation of phenolics are interrelated at the molecular level.During the early stages of development,non-glandular trichomes show strong morphological similarities to glandular ones such as the balloon-like apical cells with numerous phenolics.At later developmental stages,and during secondary wall thickening,phenolics are transferred to the cell walls of the trichomes.Due to the diff use deposition of phenolics in the cell walls,trichomes provide protection against UV-B radiation by behaving as optical fi lters,screening out wavelengths that could damage sensitive tissues.Protection from strong visible radiation is also aff orded by increased surface light refl ectance.Moreover,the mixtures of trichome phenolics represent a superfi-cial chemical barrier that provides protection against biotic stress factors such as herbivores and pathogens.Although the cells of some trichomes die at maturity,they can modulate their quantitative and qualitative characteristics during development,depending on the prevailing conditions of the external biotic or abiotic environment.In fact,the structure and chemical constituents of trichomes may change due to the particular light regime,herbivore damage,wounding,water stress,salinity and the presence of heavy metals.Hence,trichomes represent dynamic protective structures that may greatly aff ect the outcome of many plant–environment interactions.展开更多
基金funded by the National Natural Science Foundation of China (30771387)the Commonweal Research Program of Agricultural Science of China (nyhyzx3-16)+2 种基金the Research Foundation of Education Bureau of Hunan Province, China (06B027)the Natural Science Foundation of Hunan Province in China (10JJ2030)the Scientific Research Starting Foundation for Doctors of Hunan University of Science and Technology, China (E50563)
文摘WRKY transcription factors are involved in the regulation of response to biotic and abiotic stresses in plants. A full-length cDNA clone of rice WRKY82 gene (OsWRKY82) was isolated from a cDNA library generated from leaves infected by Magnaporthe grisea. OsWRKY82 contained an entire open reading frame in length of 1 701 bp, and was predicted to encode a polypeptide of 566 amino acid residues consisting of two WRKY domains, each with a zinc finger motif of C2H2, belonging to the WRKY subgroup I. OsWRKY82 shared high identity at the amino acid level with those from Sorghum bicolor, Hordeum vulgare, and Zea mays. The transcript level of OsWRKY82 was relatively higher in stems, leaves, and flowers, and less abundant in grains. It was induced by inoculation with M. grisea and Rhizoctonia solani. However, the inducible expression in incompatible rice-M. grisea interactions was earlier and greater than that in compatible interactions. The expression of OsWRKY82 was up-regulated by methyl jasmonate and ethephon, whereas salicylic acid exerted no effects on its expression. Moreover, OsWRKY82 exhibited transcriptional activation ability in yeast. Additionally, OsWRKY82 transcripts could be induced by wounding and heat shocking, but not by abscisic acid, cold, high salinity and dehydration. By contrast, gibberellin suppressed the expression of OsWRKY82. These indicate that OsWRKY82 is a multiply stress-inducible gene responding to both biotic and abiotic stresses, and may be involved in the regulation of defense response to pathogens and tolerance against abiotic stresses by jasmonic acid/ethylene-dependent signaling pathway.
基金The work supported by the grant Ministry of Education of the Czech Republic with co-financing from the European Union(grant“KOROLID”,CZ.02.1.01/0.0/0.0/15_003/0000336)the Czech Academy of Sciences(RVO:60077344).
文摘Members of the Pathogenesis Related(PR)10 protein family have been identified in a variety of plant species and a wide range of functions ranging from defense to growth and development has been attributed to them.PR10 protein possesses ribonuclease(RNase)activity,interacts with phytohormones,involved in hormone-mediated signalling,afforded protection against various phytopathogenic fungi,bacteria,and viruses particularly in response to biotic and abiotic stresses.The resistance mechanism of PR10 protein may include activation of defense signalling pathways through possible interacting proteins involved in mediating responses to pathogens,degradation of RNA of the invading pathogens.Moreover,several morphological changes have been shown to accompany the enhanced abiotic stress tolerance.In this review,the possible mechanism of action of PR10 protein against biotic and abiotic stress has been discussed.Furthermore,our findings also confirmed that the in vivo Nitric oxide(NO)is essential for most of environmental abiotic stresses and disease resistance against pathogen infection.The proper level of NO may be necessary and beneficial,not only in plant response to the environmental abiotic stress,but also to biotic stress.The updated information on this interesting group of proteins will be useful in future research to develop multiple stress tolerance in plants.
基金the Indian Council of Agricultural Research(ICAR)-National Institute for Plant Biotechnology,National Agricultural Higher Education Project:Centre for Advanced Agricultural Science and Technology(Grant No.1010033)ICAR-Centre for Agricultural Bioinformatics,Indian Agricultural Statistics Research Institute,New Delhi(IASRI)(Grant No.1006456).
文摘von Willebrand factor A(vWA)genes are well characterized in humans except for few BONZAI genes,but the vWA genes are least explored in plants.Considering the novelty and vital role of vWA genes,this study aimed at characterization of vWA superfamily in rice.Rice genome was found to have 40 vWA genes distributed across all the 12 chromosomes,and 20 of the 40 vWA genes were unique while the remaining shared large fragment similarities with each other,indicating gene duplication.In addition to vWA domain,vWA proteins possess other different motifs or domains,such as ubiquitin interacting motif in protein degradation pathway,and RING finger in protein-protein interaction.Expression analysis of vWA genes in available expression data suggested that they probably function in biotic and abiotic stress responses including hormonal response and signaling.The frequency of transposon elements in the entire 3K rice germplasm was negligible except for 9 vWA genes,indicating the importance of these genes in rice.Structural and functional diversities showed that the vWA genes in a blast-resistant rice variety Tetep had huge variations compared to blast-susceptible rice varieties HP2216 and Nipponbare.qRT-PCR analysis of vWA genes in Magnaporthe oryzae infected rice tissues indicated OsvWA9,OsvWA36,OsvWA37 and OsvWA18 as the optimal candidate genes for disease resistance.This is the first attempt to characterize vWA gene family in plant species.
文摘Plants are recurrently exposed to myriads of biotic and abiotic stresses leading to several biochemical and physiological variations that cause severe impacts on plant growth and survival.To overcome these challenges,plants activate two primary defense mechanisms,such as structural response(cell wall strengthening and waxy epidermal cuticle development)and metabolic changes,including the synthesis of anti-microbial compounds and proteins,especially the pathogenesis-related(PR)proteins.PR proteins are members of a super large family of defense proteins that exhibit antimicrobial activities.Their over-expression in plants provides tolerance to many abiotic and biotic stresses.PR proteins have been classified into 17 families,including PR-5–also called thaumatin-like proteins(TLPs)that involve osmotin and osmotin-like proteins(OLPs).Osmotin was first identified in tobacco(Nicotiana tabacum var.Wisconsin 38),and then its homolog proteins(OLPs)were reported from the whole plant kingdom.Osmotin and OLPs are ubiquitous in all fruits and vegetables.Their expression has been detected in various plant tissues and organs.The phylogenetic tree studies revealed that the osmotin group originated from spermatophytes.Moreover,the atomic structure of OLP has shown similarity to thaumatin and TLPs from monocot and eudicot species,which determines a strong evolutionary pressure in flowering plants for conserving thaumatin fold.This is associated with the role of these proteins against pathogens as defense molecules and to induce stress tolerance to plants against several biotic and abiotic factors.In this review,we have briefly described the development history of osmotin,including its function and mechanism to induce biotic and abiotic stress tolerance to plants.
基金supported by the National Natural Science Foundation of China (Grants Nos.30800677 and 30771329)the Natural Science Foundation of Zhejiang Province, China (Grant No. Y3080359)+1 种基金National Key Programs for Transgenic Crops (Grant Nos. 2008ZX08009-001 and 2009ZX08009-076B)Zhejiang Normal University Innovative Research Team Program, China
文摘Plant calcineurin B-like (CBL) proteins have been proposed as important Ca2+ sensors and specifically interact with CBL-interacting protein kinases (CIPKs) in plant-specific calcium signaling. Here, we identified and isolated 15 CIPK genes in a japonica rice variety Nipponbare based on the predicted sequences of rice CIPK gene family. Gene structure analysis showed that these 15 genes were divided into intron-less and intron-rich groups, and OsCIPK3 and OsCIPK24 exhibited alternative splicing in their mature process. The phylogenetic analyses indicated that rice CIPKs shared an ancestor with Arabidopsis and poplar CIPKs. Analyses of gene expression showed that these OsCIPK genes were differentially induced by biotic stresses such as bacterial blight and abiotic stresses (heavy metal such as Hg2+, high salinity, cold and ABA). Interestingly, five OsCIPK genes, OsCIPK1, 2, 10, 11 and 12, were transcriptionally up-regulated after bacterial blight infection whereas four OsCIPK genes, OsCIPK2, 10, 11 and 14, were induced by all treatments, indicating that some of OsCIPK genes are involved in multiple stress response pathways in plants. Our finding suggests that CIPKs play a key role in both biotic and abiotic stress responses.
基金Supported by Anhui Provincial Natural Science Research Project for Colleges and Universities(KJ2012Z105)Youth Project of the National Natural Science Foundation of China(31501245)
文摘Stresses are defined as a variety of environmental factors that pose adverse impacts on plant growth and survival. Rice is an important food crop, whose quality and yield may be affected by environmental stresses. MicroRNAs play an important role in response to stresses, which regulate gene expression at the post-transcription level by cleaving target mRNAs and inhibiting mRNA translation. This paper summarized the mechanism of action of miRNAs and introduced research progress of miRNAs in rice under biotic and abiotic stresses, which provided reference for revealing the functional role of rice miRNAs in stress resistance.
基金We would like to thank Dr Nam-Hai Chua (Rockefeller Univer- sity) for kindly providing the pBA002Myc vector and the Arabi- dopsis Biological Resource Center (ABRC), Ohio State University for providing ToDNA insertion lines. This work was supported by grants from National Natural Science Foundation of China (No. 30530400/90717006/30670195) to Q Xie and Y Wu, the Chinese Academy of Science (KSCX2-YW-N-010 and CXTD-S2005-2), and the (iuangdong Natural Science Foundation, China (No. 5300648) to Z Deng.
文摘The “quasi-essential element” silicon (Si) is not considered indispensable for plant growth and its accumulation varies between species largely due to differential uptake phenomena. Silicon uptake and distribution is a complex process involving the participation of three transporters (Lsi1, Lsi2 and Lsi6) and is beneficial during recovery from multiple stresses. This review focuses on the pivotal role of silicon in counteracting several biotic and abiotic stresses including nutrient imbalances, physical stresses together with uptake, transport of this metalloid in a wide variety of dicot and monocot species. The knowledge on the beneficial effects of silicon and possible Si-induced mechanisms of minimizing stress has been discussed. Accumulation of silicon beneath the cuticles fortifies the cell wall against pathogen attack. Si-induced reduction of heavy metal uptake, root-shoot translocation, chelation, complexation, upregulation of antioxidative defense responses and regulation of gene expression are the mechanisms involved in alleviation of heavy metal toxicity in plants. Silicon further improves growth and physiological attributes under salt and drought stress. Effective use of silicon in agronomy can be an alternative to the prevalent practice of traditional fertilizers for maintaining sustainable productivity. Therefore, soil nutrition with fertilizers containing plant-available silicon may be considered a cost-effective way to shield plant from various stresses, improve plant growth as well as yield and attain sustainable cultivation worldwide.
文摘This unique study evaluates the effects of Ralstonia solanacearum (Rs) induced biotic stress in two cultivars, Zingiber officinale (ginger) and Lycopersicon esculentum (tomato). They were grown in pots and hydroponic systems with controls;to induce biotic stress, about 8 × 104 colony forming units of Rs suspension was injected into the healthy test plants. Upon induction of Rs stress, highly significant (p 0.01) biochemical changes (%) were noticed in respect to controls: carbohydrate content was generally high in both plants;while they showed decreased starch and protein contents;phenolics showed a swing of decrease or increase between pot and hydroponic systems;and all plants in general showed higher (3-6 fold) proline content upon induction of biotic stress. Regarding oxidative stress isozymes (OSE), superoxide dismutase (EC 1.15.1.1) isozymes were normally 3, but treated hydroponics had 4 with comparable relative mobility values;peroxidase (EC 1.11.1.7) isozymes were generally 2, except for treated hydroponic tomato. Briefly, Rs induced biotic stress caused wilt symptoms in ginger, but did not affect tomato though its biochemical and OSE patterns especially in those grown as hydroponics were elicited to significantly higher levels.
基金the regional durum wheat research project of the Dryland Agricultural Research Institute(DARI)of Iransupported by the Agricultural Research and Education Organization(AREEO)
文摘Biotic and abiotic stresses are major limiting factors for high crop productivity worldwide. A landrace collection consisting of 380 durum wheat(Triticum turgidum L. var. durum) entries originating in several countries along with four check varieties were evaluated for biotic stresses:yellow rust(Puccinia striiformis Westendorf f. sp. tritici) and wheat stem sawfly(WSS) Cephus cinctus Norton(Hymenoptera: Cephidae), and abiotic stresses: cold and drought. The main objectives were to(i) quantify phenotypic diversity and identify variation in the durum wheat landraces for the different stresses and(ii) characterize the agronomic profiles of landraces in reaction to the stresses. Significant changes in reactions of landraces to stresses were observed.Landraces resistant to each stress were identified and agronomically characterized.Percentage reduction due to the stresses varied from 11.4%(yellow rust) to 21.6%(cold stress) for 1000-kernel weight(TKW) and from 19.9(yellow rust) to 91.9%(cold stress) for grain yield. Landraces from Asia and Europe showed enhanced genetic potential for both grain yield and cold tolerance under highland rainfed conditions of Iran. The findings showed that TKW and yield productivity could be used to assess the response of durum wheat landraces to different stresses. In conclusion, landraces showed high levels of resistance to both biotic and abiotic stresses, and selected landraces can serve in durum wheat breeding for adaptation to cold and drought-prone environments.
基金supported by Princeton University’s Scott and Tuttle FundsThe Department of Science and Technology(DST,India)INSPIRE Faculty Award DST/INSPIRE/04/2015/0003110。
文摘The late Maastrichtian witnessed substantial surges in Deccan volcanism,prompting the hypothesis that these voluminous pulses may have instigated repeated episodes of ocean acidification during this period.The Cretaceous-Palaeogene(K/Pg)boundary at Bidart(France)is preceded by a~0.5 m thick interval with geochemical and taphonomic vestiges of an ocean acidification event linked with Deccan volcanism.New planktic foraminifera census and morphometric data now confirm biotic stress conditions related to acidification in the Deccan benchmark interval.The absolute abundance data of larger(>150μm)heavily calcified planktic morphogroups show fluctuating populations throughout zone CF1(spanning the final~225 ky),lowest peaks within the Deccan benchmark,and a demographic collapse(>90%)at the K/Pg boundary.The analyzed species are generally reduced in size,with thinner test walls in this~0.5 m interval,indicating the likelihood of calcification stress as a contributor to the overall biotic stress.At the K/Pg boundary,maximum biotic stress is recorded in all the tested faunal proxies.A preliminary graphic correlation of zone CF1 at Bidart with the auxiliary GSSP at Elles(Tunisia)constrains the Deccan benchmark interval of high biotic stress to the final~58ky of the late Maastrichtian,culminating in the K/Pg mass extinction.The volcanogenic Hg peaks coincident with faunal and taphonomic evidence of ocean acidification strengthen the Deccan-related ocean acidification hypothesis.
基金partially funded by the Chiang Mai University (Grant No. RG25/2566)the Thailand Rice Science Research Hub of Knowledge (NRCT: N34E670027), Thailand
文摘The aroma of fragrant rice is one of the grain quality attributes that significantly influenceconsumer preferences and prices in world markets. The volatile compound 2-acetyl-1-pyrroline (2AP) isrecognized as a key component of the aroma in fragrant rice. The variation in grain 2AP content amongvarious fragrant rice varieties is associated with the expression of the badh2 gene, with 19 alleles havingbeen identified so far. The grain 2AP content is strongly influenced by environmental and managementfactors during cultivation as well as post-harvest conditions. This review pinpointed the major abiotic andbiotic factors that control grain 2AP content. Abiotic factors refer to water, temperature, light quality,fertilizer application (both macro- and micro-nutrients), and soil properties, including salinity, while bioticfactors include microorganisms that produce aromatic compounds, thus influencing the grain aroma infragrant rice. Post-harvest management, including storage and drying conditions, can significantly impactthe grain 2AP content, and proper post-harvest conditions can intensify the grain aroma. This reviewsuggests that there are rice varieties that can serve as potential sources of genetic material for breedingrice varieties with high grain aroma content. It offers an overview of recent research on the major factorsaffecting the aroma content in fragrant rice. This knowledge will facilitate further research on theproduction of high-quality rice to meet the demands of farmers and consumers.
基金supported by the National Natural Science Foundation of China(31370302)"the Hundred Talents Program"(54Y154761001076 and 29Y32963100263) to Zhulong Chan+2 种基金by the National Natural Science Foundation of China(31200194)Youth Innovation Promotion Association of Chinese Academy of Sciences(29Y42937100437)the Knowledge Innovative Key Program of Chinese Academy of Sciences(55Y45544600544) to Haitao Shi
文摘Hydrogen sulfide (H2S) is an important gaseous molecule in various plant developmental processes and plant stress responses. In this study, the transgenic Arabidopsis thaliana plants with modulated expressions of two cysteine desulfhydrases, and exogenous H2S donor (sodium hydrosulfide, NariS) and H2S scavenger (hypotaurine, HT) pre-treated plants were used to dissect the involvement of H2S in plant stress responses. The cysteine desulfhydrases overexpressing plants and NariS pre-treated plants exhibited higher endogenous H2S level and improved abiotic stress tolerance and biotic stress resistance, while cysteine desulfhydrases knockdown plants and HT pre-treated plants displayed lower endogenous H2S level and decreased stress resistance. Moreover, H2S upregulated the transcripts of multiple abiotic and biotic stress-related genes, and inhibited reactive oxygen species (ROS) accumulation. Interest- ingly, MlR393-mediated auxin signaling including MIR393a/b and their target genes (TIR1, AFB1, AFB2, and AFB3) was transcrip-tionally regulated by H2S, and was related with H2S-induced antibacterial resistance. Moreover, H2S regulated 50 carbon metabolites including amino acids, organic acids, sugars, sugar alcohols, and aromatic amines. Taken together, these results indicated that cysteine desulfhydrase and H2S conferred abiotic stress tolerance and biotic stress resistance, via affecting the stress-related gene expressions, ROS metabolism, metabolic homeostasis, and MIR393-targeted auxin receptors.
基金supported by DARPA’s Insect Allies Program,of which ING,PR,and GLW were team members.
文摘Agricultural production is hampered by disease,pests,and environmental stresses.To minimize yield loss,it is important to develop crop cultivars with resistance or tolerance to their respective biotic and abiotic constraints.Transformation techniques are not optimized for many species and desirable cultivars may not be amenable to genetic transformation,necessitating inferior cultivar usage and time-consuming introgression through backcrossing to the preferred variety.Overcoming these limitations will greatly facilitate the development of disease,insect,and abiotic stress tolerant crops.One such avenue for rapid crop improvement is the development of viral systems to deliver CRISPR/Cas-based genome editing technology to plants to generate targeted beneficial mutations.Viral delivery of genomic editing constructs can theoretically be applied to span the entire host range of the virus utilized,circumventing the challenges associated with traditional transformation and breeding techniques.Here we explore the types of viruses that have been optimized for CRISPR/Cas9 delivery,the phenotypic outcomes achieved in recent studies,and discuss the future potential of this rapidly advancing technology.
基金supported by grants from the National Key R&D Program of China(2021YFD1400800)the Chinese Natural Science Foundation(Grant 31922075,32172504)the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDPB16).
文摘As sessile organisms,plants have to cope with environmental change and numerous biotic and abiotic stress.Upon perceiving environmental cues and stress signals using different types of receptors,plant cells initiate immediate and complicated signaling to regulate cellular processes and respond to stress.Receptor-like cytoplasmic kinases(RLCKs)transduce signals from receptors to cellular components and play roles in diverse biological processes.Recent studies have revealed the hubbing roles of RLCKs in plant responses to biotic stress.Emerging evidence indicates the important regulatory roles of RLCKs in plant responses to abiotic stress,growth,and development.As a pivot of cellular signaling,the activity and stability of RLCKs are dynamically and tightly controlled.Here,we summarize the current understanding of how RLCKs regulate plant responses to biotic and abiotic stress.
文摘Lignin is a polymer of phenylpropanoid compounds formed through a complex biosynthesis route, represented by a metabolic grid for which most of the genes involved have been sequenced in several plants, mainly in the model-plants Arabidopsis thaliana and Populus. Plants are exposed to different stresses, which may change lignin content and composition. In many cases, particularly for plant-microbe interactions, this has been suggested as defence responses of plants to the stress. Thus, understanding how a stressor modulates expression of the genes related with lignin biosynthesis may allow us to develop study-models to increase our knowledge on the metabolic control of lignin deposition in the cell wall. This review focuses on recent literature reporting on the main types of abiotic and biotic stresses that alter the biosynthesis of lignin in plants.
基金supported by the National Natural Science Foundation of China(32070214,31670267)the Fundamental Research Funds for the Central Universities(2662020SKY008).
文摘Stomatal aperture controls the balance between transpirational water loss and photosynthetic carbon dioxide(CO2)uptake.Stomata are surrounded by pairs of guard cells that sense and transduce environmental or stress signals to induce diverse endogenous responses for adaptation to environmental changes.In a recent decade,hydrogen sulfide(H2S)has been recognized as a signaling molecule that regulates stomatal movement.In this review,we summarize recent progress in research on the regulatory role of H2S in stomatal movement,including the dynamic regulation of phytohormones,ion homeostasis,and cell structural components.We focus especially on the cross talk among H2S,nitric oxide(NO),and hydrogen peroxide(H2O2)in guard cells,as well as on H2S-mediated post-translational protein modification(cysteine thiol persulfidation).Finally,we summarize the mechanisms by which H2S interacts with other signaling molecules in plants under abiotic or biotic stress.Based on evidence and clues from existing research,we propose some issues that need to be addressed in the future.
文摘The agriculture sector is no exception to the widespread usage of deep learning tools and techniques.In this paper,an automated detection method on the basis of pre-trained Convolutional Neural Network(CNN)models is proposed to identify and classify paddy crop biotic stresses from the field images.The proposed work also provides the empirical comparison among the leading CNN models with transfer learning from the ImageNet weights namely,Inception-V3,VGG-16,ResNet-50,DenseNet-121 and MobileNet-28.Brown spot,hispa,and leaf blast,three of the most common and destructive paddy crop biotic stresses that occur during the flowering and ripening growth stages are considered for the experimentation.The experimental results reveal that the ResNet-50 model achieves the highest average paddy crop stress classification accuracy of 92.61%outperforming the other considered CNN models.The study explores the feasibility of CNN models for the paddy crop stress identification as well as the applicability of automated methods to non-experts.
基金supported by the National Natural Science Foundation of China(Grant No.31701803)Changsha Natural Science Foundation,China(Grant No.kq2202336)the Special Project of Hunan Innovative Province Construction,China(Grant No.S2021ZCKPZT0004)。
文摘Despite increasing knowledge of barnyardgrass(Echinochloa crus-galli) interference with rice, relatively little is known how endophytes improve the ability of rice against barnyardgrass stress. Here, we provided a detailed temporal characterization of rice root-associated microbiomes during co-cultivation with barnyardgrass and a comparison with the microbiomes of weed-free rice plants. Alpha diversity analysis indicated that barnyardgrass had the opposite effects on endophytic bacteria and fungi in rice roots, in terms of the community diversity, richness and coverage at the rice seedling stage. Principal coordinate analysis showed that barnyardgrass had only a minor effect on the community composition of endophytes in rice roots at the rice seedling stage, but showed a significant and maximum interference at the heading stage. Rice recruited many endophytes to resist biotic stress from barnyardgrass, especially for fungi. PICRUSt(phylogenetic investigation of communities by reconstruction of unobserved states) predictive analysis indicated that 23 metabolic pathways of bacteria were overrepresented in rice. In addition, the main trophic mode of fungi was pathotroph according to FUNGuild analysis. A positive correlation between bacteria and fungi in rice roots was found via network analysis. Anaeromyxobacter, Azospira and Pseudolabrys were the vital bacteria, Phaeosphaeria and Funneliformis were the dominant fungi in maintaining the stability of the ecological network. These results provided data and a theoretical basis for the in-depth understanding of what role endophytes play in rice resistance to barnyardgrass stress and will have implications on improving the resistance of rice against biotic stress using root microbiota.
基金partially funded by the Greek General Secretariat of Research and Technologythe Greek Scholarship FoundationThe ’Empirikion’ Foundation
文摘As superficial structures,non-glandular trichomes,protect plant organs against multiple biotic and abiotic stresses.The protective and defensive roles of these epidermal appendages are crucial to developing organs and can be attributed to the excellent combination of suitable structural traits and chemical reinforcement in the form of phenolic compounds,primarily fl avonoids.Both the formation of trichomes and the accumulation of phenolics are interrelated at the molecular level.During the early stages of development,non-glandular trichomes show strong morphological similarities to glandular ones such as the balloon-like apical cells with numerous phenolics.At later developmental stages,and during secondary wall thickening,phenolics are transferred to the cell walls of the trichomes.Due to the diff use deposition of phenolics in the cell walls,trichomes provide protection against UV-B radiation by behaving as optical fi lters,screening out wavelengths that could damage sensitive tissues.Protection from strong visible radiation is also aff orded by increased surface light refl ectance.Moreover,the mixtures of trichome phenolics represent a superfi-cial chemical barrier that provides protection against biotic stress factors such as herbivores and pathogens.Although the cells of some trichomes die at maturity,they can modulate their quantitative and qualitative characteristics during development,depending on the prevailing conditions of the external biotic or abiotic environment.In fact,the structure and chemical constituents of trichomes may change due to the particular light regime,herbivore damage,wounding,water stress,salinity and the presence of heavy metals.Hence,trichomes represent dynamic protective structures that may greatly aff ect the outcome of many plant–environment interactions.