Effects of Heavy Metals and Saline-alkali on Growth,Physiology and Biochemistry of Orychophragmus violaceus

[Objective] The aim was to study on effects of heavy metals and saline-alkali on growth, physiology and biochemistry of Orychophragmus violaceus. [Method] Taken Orychophragmus violaceus as materials, growth, physiology and biochemistry were explored under stress of saline-alkali and heavy metals (light, moderate and severe saline-alkali, Pb, Pb + Cd, light saline-alkali + Pb, moderate saline-alkali + Pb, severe saline-alkali + Pb, light saline-alkali + Pb + Cd, moderate saline-alkali + Pb + Cd and severe saline-alkali + Pb + Cd) with control group set. [Result] Light stress of saline-alkali had little effect on membrane permeability, as follows: MDA contents in leaves and root systems declined by 25.6% and 9.0% compared with control group; Pb (500 mg/L) stress promoted synthetization of photosynthetic pigments, as follows: chlorophyll a and b and carotenoid increased by 0.86%, 0.69% and 6.25% than those of control group; combined stresses of Pb and Cd destroyed synthetization of photosynthetic pigments, among which carotenoid was more sensitive; under combined stresses of saline-alkali, Pb and Cd, POD and SOD activities, soluble saccharides and Pro content all increased and activities of POD and SOD in root system were both higher than those in leaves. [Conclusion] Orychophragmus violaceus is with resistance against light combined stresses of saline-alkali and Pb (500 mg/L).

Effects of Inoculation with Phosphate Solubilizing Bacteria on the Physiology,Biochemistry,and Expression of Genes Related to the Protective Enzyme System of Fritillaria taipaiensis P.Y.Li

Fritillaria taipaiensis P.Y.Li is a widely used medicinal herb in treating pulmonary diseases.In recent years,its wild resources have become scarce,and the demand for efficient artificial cultivation has significantly increased.This article is the first to apply phosphate solubilizing bacteria isolated from the rhizosphere soil of F.taipaiensis P.Y.Li to the cultivation process of F.taipaiensis P.Y.Li.The aim is to identify suitable reference strains for the artificial cultivation and industrial development of F.taipaiensis P.Y.Li by examining the effects of various phosphate solubilizing bacteria and their combinations on photosynthesis,physiological and biochemical properties,and gene expression related to the protective enzyme system in F.taipaiensis P.Y.Li.The experiment,conducted in pots at room temperature,included a control group(CK)and groups inoculated with inorganic phosphorussolubilizing bacteria:W1(Bacillus cereus),W2(Serratia plymuthica),W12(Bacillus cereus and Serratia plymuthica),and groups inoculated with organophosphorus-solubilizing bacteria:Y1(Bacillus cereus),Y2(Bacillus cereus),Y12(Bacillus cereus and Bacillus cereus),totaling seven groups.Compared to CK,most growth indices in the bacterial addition groups showed significant differences,with W12 achieving the highest values in all indices except the leaf area index.The content of photosynthetic pigments,photosynthetic parameters,and osmoregulatory substances increased variably in each bacterial treatment group.W12 exhibited the highest content of chlorophyll a and soluble protein,while W1 had the highest free proline content.The activities of peroxidase(POD),superoxide dismutase(SOD),and catalase(CAT)in all inoculated groups were higher than in CK,with significant changes in SOD and CAT activities.The malondialdehyde(MDA)content in all inoculated groups was lower than in CK,with Y12 being the lowest,at approximately 30%of CK.Gene expression corresponding to these three enzymes also increased variably,with POD expression in Y2 being the highest at 2.73 times that of CK.SOD and CAT expression in Y12 were the highest,at 1.84 and 4.39 times that of CK,respectively.These results indicate that inoculating phosphate solubilizing bacteria can enhance the growth of F.taipaiensis P.Y.Li,with the mixed inoculation groups W12 and Y12 demonstrating superior effects.This lays a theoretical foundation for selecting bacterial fertilizers in the cultivation process of F.taipaiensis P.Y.Li.

Effects of Potassium-Solubilizing Bacteria on Growth, Antioxidant Activity and Expression of Related Genes in Fritillaria taipaiensis P. Y. Li

This study aimed to examine the effects of inoculating Fritillaria taipaiensis P.Y.Li leaves with different strains ofpotassium-solubilizing bacteria (KSB), or combinations thereof, focusing on aspects of photosynthesis and physiologicaland biochemical characteristics. At present, some studies have only studied the rhizosphere microbialcommunity characteristics of F. taipaiensis and have not discussed the effects of different microbial species on thegrowth promotion of F. taipaiensis. This paper will start from the perspective of potassium-solubilizing bacteria toconduct an in-depth study. Seed cultivation commenced at the base with three different KSBs in early October2022. The growth of F. taipaiensis leaves was observed after different treatments. Both single-plant and compoundinoculations were executed. A total of eight treatment groups were established, with aseptic fertilizer and sterilizedsoil functioning as the control group. The results reveal that intercellular CO_(2) concentration (Ci), stomatal conductance(Gs), and transpiration rate (Tr) were at their apex in the S7 group. Most treatment groups exhibited anincrease in leaf area, photosynthetic pigment content, soluble sugar, soluble protein, Superoxide Dismutase(SOD), Peroxidase (POD), Catalase (CAT) activities, and proline content. The expression levels of POD, SOD,and CAT genes were evaluated, following inoculation with different KSB. The highest was the S7 group. Theinoculation with various KSB, or combinations thereof, appears to bolster the growth and development of F. taipaiensis.The composite inoculation group S7, comprising Bacillus cereus, Burkholderia cepacia, and Bacillus subtilis,manifested the most favorable impact on the diverse indices of F. taipaiensis, thereby furnishing valuableinsights for the selection of bacterial fertilizer in the artificial cultivation of F. taipaiensis.

Effect and Mechanism of Cold Tolerant Seed-Coating Agents on the Cold Tolerance of Early Indica Rice Seedlings

To better understand the effect and mechanism of cold tolerant seed-coating agents on the cold tolerance of rice seedlings, the physiological and biochemical effects of four cold tolerant seed-coating agents （HET, YKJ, YKZYJ, and the ABA seed coating agents） on two early indica rice varieties were studied under chilling stress. The results showed that the rice seedlings treated with cold tolerant seed-coating agents under chilling stress maintained dramatically higher root vigor, POD, CAT and SOD activities, and chlorophyll content, had lower MDA content and electrolyte leakage, and accumulated more soluble sugar and free proline, when compared with the control without the treatment, and finally showed lower plant injury rate. It was indicated that the cold tolerant seed coating agent improved the ability of rice seedlings in resisting to chilling stress. YKZYJ was ranked the first in terms of the efficiency in cold tolerance among the four cold tolerant seed-coating agents tested.

Research Progress of Cold Resistance Mechanism of Cassava

Cassava is vulnerable to frost and snow, so it is suitable for planting in tropical and subtropical region. Low temperature is an important environment factor affecting the growth and development and production of cassava, and the region with annual average temperature below 15 ℃ is not conducive to its normal growth and development. The improvement of cold resistance of cassava can increase the planting area and improve the yield and quality of cassava. In this study, morphological,physiological and biochemical and molecular researches on cold resistance of cassava, as well as the latest research progress,were reviewed in this paper. At the same time, some potential difficulties in the research on cold resistance of cassava were put forward, and the future work focus was also discussed.

Stress response to nanoplastics with different charges in Brassica napus L.during seed germination and seedling growth stages

Nanoplastic pollution has become a significant problem in farmland systems worldwide.However,research on the effects of nanoplastics(NPs)with different charges on field crops is still limited.In our study,NPs with different charges,including unmodified polystyrene nanoplastics(PS),positively charged polystyrene nanoplastics(PS-NH_(2)),and negatively charged polystyrene nanoplastics(PSSO3H),were investigated for their impacts on seed germination and seedling growth of rape.The results showed that seed water uptake(after 12 h),seed germination,seed vigour,and relative root elongation were all significantly reduced under exposure to NPs(200 mg/L).Similarly,remarkable decreases in plant biomass(root weight,shoot weight),growth(root length,plant height),photosynthesis ability(chlorophyll a,chlorophyll b,carotenoids),essential nutrient uptake(Fe,Mn,Zn,Cu),and plant quality(soluble protein,soluble sugar,crude fibre content)of rape seedlings were also observed after exposure to NPs.Among the three kinds of NPs,PS-NH_(2)showed stronger effects.Moreover,superoxide dismutase,peroxidase,and catalase activities of rape seedlings were changed,and the content of malondialdehyde was significantly increased under exposure to NPs.Furthermore,positively charged PS-NH_(2)showed stronger effects on the phenotype,physiology,biochemistry,nutrient uptake,and plant quality of rape.Notably,a comprehensive toxicity evaluation revealed that PS-NH_(2)had the strongest toxicity to rape.The present study provides important implications for the interaction and risk assessment of NPs and crops in soil-plant systems.

Recent Research Progress in Foxtail Millet(Setaria italica)

Foxtail millet （Setaria italica L. Beauv.）, as a significant food and fodder cereal crop, was widely cultivated in the Yellow River Valley and is still a kind of farming tradition of millet in Northern China. With the development of agriculture and the improvement of people＇s living standards, foxtail millet＇s planting area has be- come less and less in arid and semi-arid region now. However, because of its small diploid genome （1C genome size=420 Mb） and self-pollination, foxtail millet is very suitable for whole genome sequence and is used as an experimental model plant for C4 photosynthesis and biofuel research. In 2012, the completed genome sequence of foxtail millet had been successfully produced by the Beijing Genomics Institute （BGI） and US Department of Energy Joint Genomic Institute （JGI）, respec- tively. It will be used as an experimental crop to explore many aspects of plant ar- chitecture, physiology and biochemistry, comparative and functional genomics studies in the bioenergy grasses. To systematically understand the recent research progress in foxtail millet; we summarize the following aspects in this study： germplasm, tradi- tional breeding, physiology and biochemistry, molecular marker, construction of genet- ic linkage map, gene localization, genome sequencing and comparative genome. This may be a door to open for the further development of foxtail millet in the future.