中国经典期刊如何走出国门——Journal of Integrative Plant Biology办刊实践

Journal of Integrative Plant Biology(《植物学报》英文版,以下简称JIPB,)是由中国科学院主管、中国植物学会和中国科学院植物研究所共同主办的植物学综合性英文学术期刊。JIPB已被SCI、Google Scholar、PubMed、Chemical Abstracts、Biological Abstracts等67个国际主要检索系统收录。截至2012年,JIPB的全球订户已达1.43万家,全文下载量达19.7万次。近十多年来,曾荣获中国科学院、中国科学技术协会优秀期刊一等奖和全国优秀期刊二等奖、第一至第三届国家期刊奖、中国科学院优秀期刊特别奖、中国杰出百种期刊奖。

JA-mediated MYC2/LOX/AOS feedback loop regulates osmotic stress response in tea plant

Osmotic stress caused by low-temperature,drought and salinity was a prevalent abiotic stress in plant that severely inhibited plant development and agricultural yield,particularly in tea plant.Jasmonic acid(JA)is an important phytohormone involving in plant stress.However,underlying molecular mechanisms of JA modulated osmotic stress response remains unclear.In this study,high concentration of mannitol induced JA accumulation and increase of peroxidase activity in tea plant.Integrated transcriptome mined a JA signaling master,MYC2 transcription factor is shown as a hub regulator that induced by mannitol,expression of which positively correlated with JA biosynthetic genes(LOX and AOS)and peroxidase genes(PER).CsMYC2 was determined as a nuclei-localized transcription activator,furthermore,ProteinDNA interaction analysis indicated that CsMYC2 was positive regulator that activated the transcription of CsLOX7,CsAOS2,CsPER1 and CsPER3via bound with their promoters,respectively.Suppression of CsMYC2 expression resulted in a reduced JA content and peroxidase activity and osmotic stress tolerance of tea plant.Overexpression of CsMYC2 in Arabidopsis improved JA content,peroxidase activity and plants tolerance against mannitol stress.Together,we proposed a positive feedback loop mediated by CsMYC2,CsLOX7 and CsAOS2 which constituted to increase the tolerance of osmotic stress through fine-tuning the accumulation of JA levels and increase of POD activity in tea plant.

Soil Physico-Chemical Properties and Different Altitudes Affect Arbuscular Mycorrhizal Fungi Abundance and Colonization in Cacao Plantations of Cameroon

This study aims to investigate the abundance of AMF according to soil properties and altitudes in different cacao plantations of Cameroon. Physico-chemical analyses were made on soil samples collected from three agro-ecological zones. Soil samples were also used to evaluate directly the AMF abundance following the various altitudes and after trapping by sorghum plant. The results showed that soil properties, AMF spore abundances and colonization fluctuated significantly at different altitudes. The most represented texture was sandy loam. The bimodal zone presented a homogeneous texture (sandy loam) in all its localities. Cacao soil chemical characteristics showed that, the highest nitrogen rate (0.47%;p 0.05, Scott-Knott test) was recorded at Melong in a monomodal zone while Tonga in the Western highlands displayed the lowest rate (0.13%). Soil P concentration was significantly high in monomodal zones (Mbanga and Melong). Soil pH level indicated that the soil from Tonga in the Western highlands was neutral (pH = 6.67), and soils of other localities under study were acidic with the lowest (4.75) pH level recorded at Melong in a monomodal zone. In soil samples, the highest spore density (1.03 spores/g soil) was observed at Ntui in Bimodal zone, while the lowest spore density (0.26 spores/g soil) was observed at Bafang in the Western highlands. Root colonization showed that the sample from Bokito in a bimodal zone displayed the best frequency of mycorrhization (86.11%) while the sample from Bafang in the Western highlands recorded the lowest (27.11%). The PCA analysis highlighted that available phosphorus, pH and altitude all strongly correlated with AMF root colonization ability and can be used as a predictor of AMF colonization ability in cacao rhizosphere.

Influence of Topography on the Distribution and Structure of Woody Plants in the Senegalese Sahel (Sandy Ferlo)

This study describes the floristic composition and structure of a woody stand in the Senegalese Sahel, paying particular attention to the edaphic factors of its floristic composition. A stratified inventory considering the different relief units was adopted. Woody vegetation was surveyed using a dendrometric approach. The results obtained show that the flora is dominated by a few species adapted to drought, such as Balanites aegyptiaca (L.) Del., Calotropis procera Ait. and Boscia senegalensis (Pers.). The distribution of this flora and the structure of the ligneous plants are linked to the topography. In the lowlands, the flora is more diversified and the ligneous plants reach their optimum level of development compared with the higher relief areas. In the lowlands, there are a few woody species which, in the past, were indicative of better climatic conditions. These are Anogeissus leiocarpus (DC.), Commiphora africana (A. Rich.), Feretia apodanthera Del., Loeseneriella africana (A. Smith), Mitragyna inermis (Willd.) and Sclerocarya birrea (A. Rich). It is important that their reintroduction into reforestation projects takes account of their edaphic preference.

Floristic Diversity, Stand Structure and Plant Life Traits in the Forest-Savanna Mosaic at Ndjole (Centre Cameroon)

With the aim of assessing floristic diversity, stand structure and vegetation ecology, the present work was carried out in the savanna mosaic forest of the locality of Ndjole (Centre Cameroon). A total of 30 floristic plots of 40 m × 40 m (1600 m2) were delineated in the different ecosystems (forest, forest-savanna contact zone and the savanna). Within each plot, all individuals with a diameter at breast height ≥ 10 cm at 1.30 m were taken into account. ANOVA was used to compare the means of the diversity indices of the different ecosystems, and the DUNCAN test at 5% significance level (XLSTAT 2016) to separate these means. A total of 85 species belonging to 67 genera and 33 families were recorded. That is, 68 species in semi-caducifolia forest, 45 in forest-savanna contact zone and 18 in savanna. Urticaceae, Combretaceae, Apocynaceae, Myristicaceae and Euphorbiaceae are the most diverse families in the forest. On the other hand, in contact zones, the Euphorbiaceae, Fabaceae, Annonaceae and Moraceae families are the most diversified, while in the savannas, the Combretaceae, Fabaceae and Annonaceae families are the most diversified. Shannon’s diversity index values (1.7 to 2.37 bits) reflect low specific diversity;Piélou’s equitability (0.86 to 0.9) shows good distribution of individuals within species. The diametric structure of woody species shows an inverted “J” shape in all plant communities. This indicates a high regeneration potential characterized by a greater number of small trees than large trees. Mesophanerophytes and megaphanerophytes are dominant in forests and forest-savanna contact zones, and microphanerophytes in the savannas. Endozoochory is the main mode of diaspore dissemination. As regards the distribution of phytogeographical types, it shows the overall dominance of Guineo-Congolese species in all plant communities. Our study provides detailed data on forest-savanna floristic and plant life traits in the mosaic and recommends further studies on the impact of environmental parameter variations on the forest encroachment into savanna.

Assessing the Efficacy of Lemongrass (Cymbopogon citratus) and Sambong (Blumea balsamifera) Extracts in Combating Black Pod Disease: Sustainable Solutions for Controlling Phytophthora megakarya in Cameroon’s Cocoa Plantations

The use of plant extracts as antifungal agents is gaining increasing attention, particularly for the control of black pod disease in cocoa. Despite extensive research, current strategies haven’t been entirely effective. This study evaluated the effectiveness of Cymbopogon citratus and Blumea balsamifora leaf extracts, both individually and in combination, against Phytophthora megakarya. We assessed the efficacy of the most promising combination (75% B. balsamifera, 25% C. citratus) after storage at room temperature for up to 9 days. Agar microdilution and in vivo bioassays were conducted to determine antifungal susceptibility and effectiveness. Blumea extract exhibited the highest overall inhibitory activity, with the lowest minimum inhibitory concentration (117 µl mL−1) while C. citratus had a narrower range of MIC (146 to 233 µl mL−1). The combination of C. citratus and B. balsamifera demonstrated a synergistic effect against P. megakarya, achieving growth inhibition on V8 media (92.72 ± 4.20% to 100%) and on artificially infected detached pod cortex (92.24 ± 4.53% to 98.75 ± 1.25%), which was not significantly different from the positive control (Ridomil). Furthermore, this combination maintained its effectiveness for up to 9 days at room temperature. These findings suggest that combining plant extracts can enhance their antifungal properties.

Morphological Characterization of Arbuscular Mycorrhizal Fungi Associated with the Rhizosphere According to the Age of Xanthosoma sagittifolium L. Schott Plants in the Field

The objective of this work was to carry out a morphological characterization of arbuscular mycorrhizal fungi in the rhizosphere of Xanthosoma sagittifolium L. Schott plants. The plant material used was the white and red cultivars of X. sagittifolium, belonging to age intervals of 3 - 6, 6 - 9, and 9 - 12 months. Three harvest sites were chosen in the Central Region of Cameroon. In each site, soil from the rhizosphere and plant roots was collected in a randomized manner. In the field, the agronomic parameters were evaluated. The physicochemical characteristics of the soils, the mycorrhization index, and the morphological characterization of the mycorrhizal types of each site were carried out. The results obtained show that the agronomic growth parameters varied significantly using the Student Newman and Keuls Test depending on the harvest sites. The soils’ pH in all sites was acidic and ranged between 4.6 and 5.8. The Nkometou site has a loamy texture while the Olembe and Soa sites have loam-clay-sandy and loam-clay textures respectively. The highest mycorrhization frequencies appeared at the Nkometou site, with 75 and 87.33% of the white and red cultivars plant roots at 6 - 9 and 3 - 6 months. The relative abundance of AMF arbuscular mycorrhizal fungal spores in the rhizosphere of X. sagittifolium plants varied with age and cultivar. There were 673 spores between 9 - 12 months in Nkometou in the red cultivar. Six AMF genera were identified in all the different soils collected: Acaulospora sp., Funneliformis sp., Gigaspora sp., Glomus sp., Scutellospora sp., and Septoglomus sp. The genus Glomus sp. was the most present at all age intervals in both cultivars.

Regeneration Status, Population Structure and Floristic Composition of Woody Plant Species in Sheleko Medicinal Natural Forest, South Gondar Zone, North West Ethiopia

Ethiopia is one of the countries in the world endowed with rich biological resources. However, due to human impacts, the forest cover in Ethiopia has been decreasing rapidly. The study was carried out with the purpose of finding out the Regeneration Status, Population Structure and Floristic composition of Woody Plant Species in Sheleko Medihanialem Natural Forest in Gondar, North West Ethiopia, from October 2019 to September 2020. The systematic vegetation sampling method was used to collect data from Fifty plots of 20 m × 20 m (400 m2) along five line transects. In addition, five, 5 m × 5 m subplots were laid within the main plot to sample seedlings and saplings. The floristic composition and population structure of woody individuals of trees and shrubs with a diameter at breast height (DBH) ≥ 2.5 cm and height ≥ 2 m were measured. DBH ≤ 2.5 cm and less than 1 m height were considered as seedlings and DBH ≥ 2.5 cm and height of 1 - 2 m as saplings. Vegetation data of density, frequency, basal area, and importance value index were computed. A total of 65 woody plant species in 54 genera and 34 plant families were recorded. Fabaceae, Moraceae and Euphorbiaceae were the dominant families in terms of species richness. Woody species densities for mature individuals were 2202.5 stems∙ha−1, seedling 2419.2 stems∙ha−1 and sapling 1737.6 stems∙ha−1. The forest was dominated by small-sized/young trees and shrubs, indicating the status of secondary growth and/or regeneration.

Exploring the impact of high density planting system and deficit irrigation in cotton(Gossypium hirsutum L.):a comprehensive review

Lessons learned from past experiences push for an alternate way of crop production.In India,adopting high density planting system(HDPS)to boost cotton yield is becoming a growing trend.HDPS has recently been considered a replacement for the current Indian production system.It is also suitable for mechanical harvesting,which reducing labour costs,increasing input use efficiency,timely harvesting timely,maintaining cotton quality,and offering the potential to increase productivity and profitability.This technology has become widespread in globally cotton growing regions.Water management is critical for the success of high density cotton planting.Due to the problem of freshwater availability,more crops should be produced per drop of water.In the high-density planting system,optimum water application is essential to control excessive vegetative growth and improve the translocation of photoassimilates to reproductive organs.Deficit irrigation is a tool to save water without compromising yield.At the same time,it consumes less water than the normal evapotranspiration of crops.This review comprehensively documents the importance of growing cotton under a high-density planting system with deficit irrigation.Based on the current research and combined with cotton production reality,this review discusses the application and future development of deficit irrigation,which may provide theoretical guidance for the sustainable advancement of cotton planting systems.

Predicting changes in the suitable habitats of six halophytic plant species in the arid areas of Northwest China

In the context of changes in global climate and land uses,biodiversity patterns and plant species distributions have been significantly affected.Soil salinization is a growing problem,particularly in the arid areas of Northwest China.Halophytes are ideal for restoring soil salinization because of their adaptability to salt stress.In this study,we collected the current and future bioclimatic data released by the WorldClim database,along with soil data from the Harmonized World Soil Database(v1.2)and A Big Earth Data Platform for Three Poles.Using the maximum entropy(MaxEnt)model,the potential suitable habitats of six halophytic plant species(Halostachys caspica(Bieb.)C.A.Mey.,Halogeton glomeratus(Bieb.)C.A.Mey.,Kalidium foliatum(Pall.)Moq.,Halocnemum strobilaceum(Pall.)Bieb.,Salicornia europaea L.,and Suaeda salsa(L.)Pall.)were assessed under the current climate conditions(average for 1970-2000)and future(2050s,2070s,and 2090s)climate scenarios(SSP245 and SSP585,where SSP is the Shared Socio-economic Pathway).The results revealed that all six halophytic plant species exhibited the area under the receiver operating characteristic curve values higher than 0.80 based on the MaxEnt model,indicating the excellent performance of the MaxEnt model.The suitability of the six halophytic plant species significantly varied across regions in the arid areas of Northwest China.Under different future climate change scenarios,the suitable habitat areas for the six halophytic plant species are expected to increase or decrease to varying degrees.As global warming progresses,the suitable habitat areas of K.foliatum,S.salsa,and H.strobilaceum exhibited an increasing trend.In contrast,the suitable habitat areas of H.glomeratus,S.europaea,and H.caspica showed an opposite trend.Furthermore,considering the ongoing global warming trend,the centroids of the suitable habitat areas for various halophytic plant species would migrate to different degrees,and four halophytic plant species,namely,S.salsa,H.strobilaceum,H.glomeratus,and H.capsica,would migrate to higher latitudes.Temperature,precipitation,and soil factors affected the possible distribution ranges of these six halophytic plant species.Among them,precipitation seasonality(coefficient of variation),precipitation of the warmest quarter,mean temperature of the warmest quarter,and exchangeable Na+significantly affected the distribution of halophytic plant species.Our findings are critical to comprehending and predicting the impact of climate change on ecosystems.The findings of this study hold significant theoretical and practical implications for the management of soil salinization and for the utilization,protection,and management of halophytes in the arid areas of Northwest China.

Plant salt tolerance and Na^+ sensing and transport

Salinity is a global challenge to agricultural production. Understanding Na^+ sensing and transport in plants under salt stress will be of benefit for breeding robustly salt-tolerant crop species. In this review, first, possible salt stress sensor candidates and the root meristem zone as a tissue harboring salt stress-sensing components are proposed. Then,the importance of Na^+ exclusion and vacuolar Na^+ sequestration in plant overall salt tolerance is highlighted. Other Na^+ regulation processes, including xylem Na^+ loading and unloading, phloem Na^+ recirculation, and Na^+ secretion, are discussed and summarized.Along with a summary of Na^+ transporters and channels, the molecular regulation of Na^+ transporters and channels in response to salt stress is discussed. Finally, some largely neglected issues in plant salt stress tolerance, including Na^+ concentration in cytosol and the role of Na^+ as a nutrient, are reviewed and discussed.

Tea plant genomics:achievements,challenges and perspectives

Tea is among the world’s most widely consumed non-alcoholic beverages and possesses enormous economic,health,and cultural values.It is produced from the cured leaves of tea plants,which are important evergreen crops globally cultivated in over 50 countries.Along with recent innovations and advances in biotechnologies,great progress in tea plant genomics and genetics has been achieved,which has facilitated our understanding of the molecular mechanisms of tea quality and the evolution of the tea plant genome.In this review,we briefly summarize the achievements of the past two decades,which primarily include diverse genome and transcriptome sequencing projects,gene discovery and regulation studies,investigation of the epigenetics and noncoding RNAs,origin and domestication,phylogenetics and germplasm utilization of tea plant as well as newly developed tools/platforms.We also present perspectives and possible challenges for future functional genomic studies that will contribute to the acceleration of breeding programs in tea plants.

From leaf to whole-plant water use efficiency(WUE)in complex canopies:Limitations of leaf WUE as a selection target

Plant water use efficiency(WUE) is becoming a key issue in semiarid areas, where crop production relies on the use of large volumes of water. Improving WUE is necessary for securing environmental sustainability of food production in these areas. Given that climate change predictions include increases in temperature and drought in semiarid regions,improving crop WUE is mandatory for global food production. WUE is commonly measured at the leaf level, because portable equipment for measuring leaf gas exchange rates facilitates the simultaneous measurement of photosynthesis and transpiration. However,when those measurements are compared with daily integrals or whole-plant estimates of WUE, the two sometimes do not agree. Scaling up from single-leaf to whole-plant WUE was tested in grapevines in different experiments by comparison of daily integrals of instantaneous water use efficiency [ratio between CO2assimilation(AN) and transpiration(E); AN/E] with midday AN/E measurements, showing a low correlation, being worse with increasing water stress. We sought to evaluate the importance of spatial and temporal variation in carbon and water balances at the leaf and plant levels. The leaf position(governing average light interception) in the canopy showed a marked effect on instantaneous and daily integrals of leaf WUE. Night transpiration and respiration rates were also evaluated, as well as respiration contributions to total carbon balance. Two main components were identified as filling the gap between leaf and whole plant WUE: the large effect of leaf position on daily carbon gain and water loss and the large flux of carbon losses by dark respiration. These results show that WUE evaluation among genotypes or treatments needs to be revised.

Maintenance of mesophyll potassium and regulation of plasma membrane H^+-ATPase are associated with physiological responses of tea plants to drought and subsequent rehydration

Drought stress is one of the main factors limiting yield in tea plants. The plant cell's ability to preserve K^+homeostasis is an important strategy for coping with drought stress. Plasma membrane H^+-ATPase in the mesophyll cell is important for maintaining membrane potential to regulate K^+transmembrane transport. However, no research to date has investigated the possible relationship between plasma membrane H^+-ATPase and mesophyll K^+retention in tea plants under drought and subsequent rehydration conditions. In our experiment, drought stress inhibited plasma membrane H^+-ATPase activities and induced net H^+influx, leading to membrane potential depolarization and inducing a massive K^+efflux in tea plant mesophyll cells. Subsequent rehydration increased plasma membrane H^+-ATPase activity and induced net H^+efflux, leading to membrane potential hyperpolarization and thus lowering K^+loss. A first downregulated and then upregulated plasma membrane H^+-ATPase protein expression level was also observed under drought and subsequent rehydration treatment, a finding in agreement with the change of measured plasma membrane H^+-ATPase activities. Taken together, our results suggest that maintenance of mesophyll K^+in tea plants under drought and rehydration is associated with regulation of plasma membrane H^+-ATPase activity.

Genome-wide identification and characterization of the bHLH gene family in an ornamental woody plant Prunus mume

The basic helix-loop-helix(bHLH)transcription factor family is the second-largest family in plants,where it plays essential roles in development,and the responses to multiple abiotic and biotic stressors.However,little information is available about this gene family in Prunus mume,which is widely cultivated in East Asia as an ornamental fruit tree.Here,100 PmbHLH genes were identified,and their evolution and functions were explored in P.mume for the first time.The PmbHLH genes were classified into 21 subfamilies.The chromosomal distribution,physicochemical properties,bHLH domain,conserved motif,and intron/exon compositions were also analyzed.Furthermore,the evolutionary pattern,divergence time of the PmbHLH family,and genetic relationships among P.mume,Arabidopsis thaliana,and Prunus persica and Fragaria vesca of Rosaceae were explored.The functional prediction analysis of these PmbHLHs indicated that their functions varied,and included participating in the formation of organs and tissues,responding to stress,and the biosynthesis and metabolism of hormones and other secondary metabolites.Interestingly,expression analyses of PmbHLHs also revealed diverse expression patterns.Most of the PmbHLH genes were highly expressed in roots and stems,and a few were highly expressed in leaves,buds,and fruits,indicating tissue expression specificity.Eight PmbHLH genes,which were upregulated during low-temperature stress,may have critical roles in the response to cold stress.Ten PmbHLHs were differentially expressed between weeping and upright branches in a P.mume F_(1) population.These results shed light on the structure and evolution of the PmbHLH gene family,and lay a foundation for further functional studies of the bHLH genes.

GOLDEN 2-LIKE transcription factors regulate chlorophyll biosynthesis and flavonoid accumulation in response to UV-B in tea plants

Flavonoids are critical secondary metabolites that determine the health benefits and flavor of tea,while chlorophylls are important contributors to the appearance of tea.However,transcription factors(TFs)that can integrate both chlorophyll biosynthesis and flavonoid accumulation in response to specific light signals are rarely identified.In this study,we report that the GOLDEN 2-LIKE TF pair,CsGLK1 and CsGLK2,orchestrate UV-B-induced responses in the chlorophyll biosynthesis and flavonoid accumulation of tea leaves.The absence of solar UV-B reduced the transcriptional expression of CsGLKs in the tea leaves and was highly correlated with a decrease in flavonoid levels(especially flavonol glycosides)and the expression of genes and TFs involved in chlorophyll biosynthesis and flavonoid accumulation.In vivo and in vitro molecular analyses showed that CsGLKs could be regulated by the UV-B signal mediator CsHY5,and could directly bind to the promoters of gene and TF involved in light-harvesting(CsLhcb),chlorophyll biosynthesis(CsCHLH,CsHEMA1,and CsPORA),and flavonoid accumulation(CsMYB12,CsFLSa,CsDFRa,and CsLARa),eventually leading to UV-B-induced responses in the chlorophylls and flavonoids of tea leaves.Furthermore,UV-B exposure increased the levels of total flavonoids,CsGLK1 protein,and expression of CsGLKs and target genes in the tea leaves.These results indicate that CsGLKs may modulate tea leaf characteristics by regulating chlorophyll biosynthesis and flavonoid accumulation in response to solar UV-B.As the first report on UV-B-induced changes in flavonoid and chlorophyll regulation mediated by CsGLKs,this study improves our understanding of the environmental regulations regarding tea quality and sheds new light on UV-B-induced flavonoid responses in higher plants.

Mapping QTL underlying tuber starch content and plant maturity in tetraploid potato

Tuber starch content and plant maturity are two important agronomic traits of potato. To investigate the complex genetic basis of these traits in the cultivated potato, as well as the relationship between them, we developed a linkage map in a tetraploid population of 192 clones derived from the cross Longshu 8 × Zaodabai and mapped quantitative trait loci(QTL) for tuber starch content and plant maturity using data collected in three diverse environments over two years. We detected eleven QTL for tuber starch content distributed on seven chromosomes, of which four, on chromosomes I, II, and VIII, were expressed in at least three environments. For plant maturity, we identified six QTL on chromosomes II, IV,V, VII, and XI, one of which, on chromosome V, showed LOD peaks ranging from 45.2 to 62.5 cM and explained 21.6%–26.6% of phenotypic variation was expressed in five of the six environments. Because the reproducible QTL for plant maturity and tuber starch content mapped to different chromosomes and neither overlapping QTL, nor any genetic interaction between QTL were detected, we infer that tuber starch content and plant maturity are controlled by independent genetic loci. This inference supports the prospect of breeding potato for both early maturity and high starch content.

CsbZIP1-CsMYB12 mediates the production of bitter-tasting flavonols in tea plants (Camellia sinensis) through a coordinated activator–repressor network

Under high light conditions or UV radiation,tea plant leaves produce more flavonols,which contribute to the bitter taste of tea;however,neither the flavonol biosynthesis pathways nor the regulation of their production are well understood.Intriguingly,tea leaf flavonols are enhanced by UV-B but reduced by shading treatment.CsFLS,CsUGT78A14,CsMYB12,and CsbZIP1 were upregulated by UV-B radiation and downregulated by shading.CsMYB12 and CsbZIP1 bound to the promoters of CsFLS and CsUGT78A14,respectively,and activated their expression individually.CsbZIP1 positively regulated CsMYB12 and interacted with CsMYB12,which specifically activated flavonol biosynthesis.Meanwhile,CsPIF3 and two MYB repressor genes,CsMYB4 and CsMYB7,displayed expression patterns opposite to that of CsMYB12.CsMYB4 and CsMYB7 bound to CsFLS and CsUGT78A14 and repressed their CsMYB12-activated expression.While CsbZIP1 and CsMYB12 regulated neither CsMYB4 nor CsMYB7,CsMYB12 interacted with CsbZIP1,CsMYB4,and CsMYB7,but CsbZIP1 did not physically interact with CsMYB4 or CsMYB7.Finally,CsPIF3 bound to and activated CsMYB7 under shading to repress flavonol biosynthesis.These combined results suggest that UV activation and shading repression of flavonol biosynthesis in tea leaves are coordinated through a complex network involving CsbZIP1 and CsPIF3 as positive MYB activators and negative MYB repressors,respectively.The study thus provides insight into the regulatory mechanism underlying the production of bitter-tasting flavonols in tea plants.

Ubiquitination-mediated protein degradation and modification:an emerging theme in plant-microbe interactions

Post-translational modification is central to protein stability and to the modulation of protein activity. Various types of protein modification, such as phosphorylation, methylation, acetylation, myristoylation, glycosylation, and ubiquitination, have been reported. Among them, ubiquitination distinguishes itself from others in that most of the ubiquitinated proteins are targeted to the 26S proteasome for degradation. The ubiquitin/26S proteasome system constitutes the major protein degradation pathway in the cell. In recent years, the importance of the ubiquitination machinery in the control of numerous eukaryotic cellular functions has been increasingly appreciated. Increasing number of E3 ubiquitin ligases and their substrates, including a variety of essential cellular regulators have been identified. Studies in the past several years have revealed that the ubiquitination system is important for a broad range of plant developmental processes and responses to abiotic and biotic stresses. This review discusses recent advances in the functional analysis of ubiquitination-associated proteins from plants and pathogens that play important roles in plant-microbe interactions.

Carotenoid Pigment Accumulation in Horticultural Plants

Carotenoids are a group of widely distributed natural pigments.They give many horticultural plants the bright red,orange,and yellow colors,as well as the aroma and flavor.Carotenoids enhance the health value and represent an essential quality trait of horticultural products.Significant efforts have been made to correlate specific carotenoid production with pathway gene expression.Some transcription factors that directly regulate transcription of the pathway genes have been identified.Horticultural crops have evolved with complicated and multifaceted regulatory mechanisms to generate the enormous diversity in carotenoid content and composition.However,the diverse and complex control of carotenoid accumulation is still not well understood.In this review,we depict carotenoid accumulation pathways and highlight the recent progress in the regulatory control of carotenoid accumulation in horticultural plants.Because of the critical roles of chromoplasts for carotenoid hyperproduction,we evaluate chromoplast ultrastructures and carotenoid sequestrations.A perspective on carotenoid research in horticultural crops is provided.