Yuxian Zhang's research while affiliated with Heilongjiang Bayi Agricultural University and other places

Background Laccase (LAC) gene family plays a pivotal role in plant lignin biosynthesis and adaptation to various stresses. Limited research has been conducted on laccase genes in common beans. Results 29 LAC gene family members were identified within the common bean genome, distributed unevenly in 9 chromosomes. These members were divided into 6 distinct subclades by phylogenetic analysis. Further phylogenetic analyses and synteny analyses indicated that considerable gene duplication and loss presented throughout the evolution of the laccase gene family. Purified selection was shown to be the major evolutionary force through Ka / Ks. Transcriptional changes of PvLAC genes under low temperature and salt stress were observed, emphasizing the regulatory function of these genes in such conditions. Regulation by abscisic acid and gibberellins appears to be the case for PvLAC3, PvLAC4, PvLAC7, PvLAC13, PvLAC14, PvLAC18, PvLAC23, and PvLAC26, as indicated by hormone induction experiments. Additionally, the regulation of PvLAC3, PvLAC4, PvLAC7, and PvLAC14 in response to nicosulfuron and low-temperature stress were identified by virus-induced gene silence, which demonstrated inhibition on growth and development in common beans. Conclusions The research provides valuable genetic resources for improving the resistance of common beans to abiotic stresses and enhance the understanding of the functional roles of the LAC gene family.

Amino acid metabolism is an important factor in regulating nitrogen source assimilation and source/sink transport in soybean. Melatonin can improve plant stress resistance, but whether it affects amino acid metabolism is not known. Therefore, this study investigated whether exogenous melatonin had an effect on amino acid metabolism of soybean under drought conditions and explored its relationship with yield. The treatments were normal water supply treatment (WW), drought stress treatment (D), drought stress and melatonin treatment group (D + M), sprayed with 100 μmol/L melatonin. The effects of melatonin on amino acid metabolism and grain filling were studied by physiological and omics experiments using Kangxian 9 (drought‐sensitive variety) and Suinong 26 (drought‐resistant variety) soybean cultivars. The results showed that drought stress decreased the activity of carbon and nitrogen metabolizing enzymes, which inhibited the accumulation of dry matter and protein, and decreased the yield. In the drought‐sensitive soybean variety, glycoenzymes and amino acid synthetases synthetic genes were upregulated in melatonin‐treated soybeans, hence carbon and nitrogen metabolism enzyme activity increased, increasing the carbohydrate and amino acid contents simultaneously. This resulted in higher dry matter and yield than drought‐stressed soybean not treated with melatonin. In the drought‐resistant variety, the grain weight per plant increased by 7.98% and 6.57% in 2020 and 2021, respectively, while it increased by 23.20% and 14.07% in the drought‐sensitive variety during the respective years. In conclusion, melatonin treatment can enhance the activity of nitrogen and carbon metabolism and amino acid content by upregulating the expression of soybean metabolic pathway and related genes, thus increasing the yield of soybean under drought stress.

Compound microbial fertilizer is a new type of environmentally friendly slow-release fertilizer that can effectively improve the physical and chemical properties of the soil, significantly improve the ecological environment, and promote the sustainable development of agriculture. In this study, we conducted a field experiment to evaluate the impact of different applications of chemical fertilizer combined with composite microbial fertilizer on soil physical properties and soybean yields at Heshan Farm, Heilongjiang Province, China, during 2021–2022. Soybean varieties “Jinyuan 55” and “Keshan 1” were treated with three treatments implemented as follows: T1 (conventional fertilization), T2 (50% N fertilizer + compound microbial fertilizer), and T3 (0 N fertilizer + compound microbial fertilizer). Compared to conventional fertilization (T1 treatment), the application of composite microbial fertilizers (T2 and T3) resulted in a decrease in soil bulk density and an increase in porosity. Notably, we observed that moderate application of the composite microbial fertilizer (T3) led to a decrease in the volume fraction of clay particles and an increase in the volume fraction of sand particles. Furthermore, all treatments exhibited high content of agglomerates larger than 5 mm at 0–20 cm. The application of composite microbial fertilizers (T2 and T3) promoted the formation of large soil agglomerates and reduced the presence of micro-agglomerates smaller than 0.25 mm. In 2021–2022, The soybean yield increased by 13.02% in the T2 treatment compared with the T1 treatment and decreased by 9.34% in the T3 treatment. We concluded that the appropriate application of compound microbial fertilizer can help protect black soil, enhance the self-repair capability of black soil, and improve soybean quality in abnormal precipitation years. These results provide an actionable basis for constructing and developing green fertilizer systems for the soybean industry.

Saline‐alkali stress (SS) is a common abiotic stress affecting crop cultivation worldwide, seriously inhibiting plant growth and biomass accumulation. Melatonin has been proven to relieve the inhibition of multiple abiotic stresses on plant growth. Therefore, soybean cultivars Heihe 49 (HH49, SS‐tolerant) and Henong 95 (HN95, SS‐sensitive) were pot‐cultured in SS soil and then treated with 300 μM melatonin at the V1 stage, when the first trifoliate leaves were fully unfolded, to investigate if melatonin has an effect on SS. SS increased reactive oxygen species (ROS) accumulation in soybean leaves and thereby induced DNA oxidative damage. In addition, SS retarded cell growth and decreased the mesophyll cell size, chloroplast number, photosynthetic pigment content, which further reduced the light energy capture and electron transport rate in soybean leaves, and affected carbohydrate accumulation and metabolism. However, melatonin treatment reduced SS‐induced ROS accumulation in the soybean leaves by increasing antioxidant content and oxidase activity. Effective removal of ROS reduced SS‐induced DNA oxidative damage in the soybean leaf genome, which was represented by decreased random‐amplified polymorphic DNA polymorphism, 8‐hydroxy‐20‐deoxyguanine content, and relative density of apurinic/apyrimidinic‐sites. Melatonin treatment also increased the volume of mesophyll cells, the numbers of chloroplast and starch grains, the contents of chlorophyll a and b and carotenoids in soybean seedling leaves treated with SS, thereby increasing the efficiency of effective light capture and electron transfer and improving photosynthesis. Subsequently, carbohydrate accumulation and metabolism in soybean leaves under SS were improved by melatonin treatment, which contributes to providing basic substances and energy for cell growth and metabolism, ultimately improving soybean SS tolerance.

Background: Nitrogen nutrition is strongly associated with crop growth and development. Nitrogen application level affects leaf size as well as nitrogen content and distribution, and thus affects photosynthetic nitrogen-use efficiency (PNUE) and yield. In this study, soybean varieties "Jinyuan 55" and "Keshan 1" were treated with nitrogen as urea at: N0, 0 kg hm-2; N0.5, 60 kg hm-2; N1, 120 kg hm-2; and N1.5, 180 kg hm-2. We compared the effect of nitrogen level on plant morphology, biomass, photosynthetic physiology, nitrogen distribution, PNUE, and other soybean seedling leaf characteristics. Results: Maximum carboxylation and electron transfer, net photosynthetic rates, and PNUE of both soybean varieties showed initial significant increases with increasing nitrogen application rate and subsequent stabilization. PNUE, carboxylation system components, electron transport components, and non-photosynthetic system distribution ratios in the photosynthetic system increased and subsequently decreased with increased nitrogen application rate. The nitrogen ratio between carboxylation and electron transport systems was positively correlated with PNUE in both soybean varieties. The nitrogen ratio in light-harvesting and non-photosynthetic systems showed a linear negative correlation with PNUE. Conclusions: Overall, an appropriate nitrogen level maintained a high photosynthetic nitrogen ratio, whereas low- or high-nitrogen conditions increased or decreased the nitrogen ratio in non-photosynthetic and photosynthetic systems, respectively, thus decreasing the PNUE and photosynthetic capacity. Moreover, increased nitrogen application rate led to a decreased nitrogen ratio in the light-harvesting system and an increased nitrogen ratio of electron transport and carboxylation systems. Our results provide a theoretical basis for optimizing leaf nitrogen distribution, determining optimum nitrogen levels, and promoting soybean seedling growth.

Cytokinin oxidase/dehydrogenase (CKX) irreversibly degrades cytokinin, regulates growth and development, and helps plants to respond to environmental stress. Although the CKX gene has been well characterized in various plants, its role in soybean remains elusive. Therefore, in this study, the evolutionary relationship, chromosomal location, gene structure, motifs, cis-regulatory elements, collinearity, and gene expression patterns of GmCKXs were analyzed using RNA-seq, quantitative real-time PCR (qRT-PCR), and bioinformatics. We identified 18 GmCKX genes from the soybean genome and grouped them into five clades, each comprising members with similar gene structures and motifs. Cis-acting elements involved in hormones, resistance, and physiological metabolism were detected in the promoter regions of GmCKXs. Synteny analysis indicated that segmental duplication events contributed to the expansion of the soybean CKX family. The expression profiling of the GmCKXs genes using qRT-PCR showed tissue-specific expression patterns. The RNA-seq analysis also indicated that GmCKXs play an important role in response to salt and drought stresses at the seedling stage. The responses of the genes to salt, drought, synthetic cytokinin 6-benzyl aminopurine (6-BA), and the auxin indole-3-acetic acid (IAA) at the germination stage were further evaluated by qRT-PCR. Specifically, the GmCKX14 gene was downregulated in the roots and the radicles at the germination stage. The hormones 6-BA and IAA repressed the expression levels of GmCKX1, GmCKX6, and GmCKX9 genes but upregulated the expression levels of GmCKX10 and GmCKX18 genes. The three abiotic stresses also decreased the zeatin content in soybean radicle but enhanced the activity of the CKX enzymes. Conversely, the 6-BA and IAA treatments enhanced the CKX enzymes’ activity but reduced the zeatin content in the radicles. This study, therefore, provides a reference for the functional analysis of GmCKXs in soybean in response to abiotic stresses.

Groundnut or peanut (Arachis hypogaea) is a legume crop. Its seeds are rich in protein and oil. Aldehyde dehydrogenase (ALDH, EC: 1.2.1.3) is an important enzyme involved in detoxification of aldehyde and cellular reactive oxygen species, as well as in attenuation of lipid peroxidation-meditated cellular toxicity under stress conditions. However, few studies have been identified and analyzed about ALDH members in Arachis hypogaea. In the present study, 71 members of the ALDH superfamily (AhALDH) were identified using the reference genome obtained from the Phytozome database. A systematic analysis of the evolutionary relationship, motif, gene structure, cis-acting elements, collinearity, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment, and expression patterns was conducted to understand the structure and function of AhALDHs. AhALDHs exhibited tissue-specific expression, and quantitative real-time PCR identified significant differences in the expression levels of AhALDH members under saline-alkali stress. The results revealed that some AhALDHs members could be involved in response to abiotic stress. Our findings on AhALDHs provide insights for further study.

Introduction Melatonin is a multipotent molecule that exists widely in animals and plants and plays an active regulatory role in abiotic stresses. The B3 superfamily is a ubiquitous transcription factor with a B3 functional domain in plants, which can respond temporally to abiotic stresses by activating defense compounds and plant hormones. Despite the fact that the B3 genes have been studied in a variety of plants, their role in soybean is still unknown. Methods The regulation of melatonin on cold resistance of soybean and the response of B3 genes to cold stress were investigated by measuring biochemical indexes of soybean. Meanwhile, the genome-wide identification of B3 gene family was conducted in soybean, and B3 genes were analyzed based on phylogeny, motifs, gene structure, collinearity, and cis-regulatory elements analysis. Results We found that cold stress-induced oxidative stress in soybean by producing excessive reactive oxygen species. However, exogenous melatonin treatment could increase the content of endogenous melatonin and other hormones, including IAA and ABA, and enhance the antioxidative system, such as POD activity, CAT activity, and GSH/GSSG, to scavenge ROS. Furthermore, the present study first revealed that melatonin could alleviate the response of soybean to cold stress by inducing the expression of B3 genes. In addition, we first identified 145 B3 genes in soybean that were unevenly distributed on 20 chromosomes. The B3 gene family was divided into 4 subgroups based on the phylogeny tree constructed with protein sequence and a variety of plant hormones and stress response cis-elements were discovered in the promoter region of the B3 genes, indicating that the B3 genes were involved in several aspects of the soybean stress response. Transcriptome analysis and results of qRT-PCR revealed that most GmB3 genes could be induced by cold, the expression of which was also regulated by melatonin. We also found that B3 genes responded to cold stress in plants by interacting with other transcription factors. Discussion We found that melatonin regulates the response of soybean to cold stress by regulating the expression of the transcription factor B3 gene, and we identified 145 B3 genes in soybean. These findings further elucidate the potential role of the B3 gene family in soybean to resist low-temperature stress and provide valuable information for soybean functional genomics study.

Soya bean sprout is a nutrient-abundant vegetable. However, enzymatic browning of soya bean sprouts during storage remains a challenge. In this study, the effects of treatment with MnCl2 or ZnCl2 on the browning index, antioxidant nutrient accumulation, total antioxidant capacity and enzyme activities of phenylalanine ammonia-lyase (PAL), polyphenol oxidase (PPO), peroxidase (POD), superoxide dismutase (SOD) and catalase (CAT) were investigated in soya bean sprouts after storage at 4 °C and 90% relative humidity for 0, 7, 14 and 21 days. The results showed that postharvest treatment with 1, 2 and 10 mM MnCl2 or ZnCl2 profoundly retarded enzymatic browning in soya bean sprouts to different extents. Compared with the control, the 10 mM MnCl2 and ZnCl2 treatments drastically enhanced ascorbic acid, total thiol and phenolic content, and enhanced FRAP (ferric-reducing ability of plasma) antioxidant capacity in stored soya bean sprouts. Moreover, the MnCl2 and ZnCl2 treatments enhanced SOD, CAT and PAL but decreased PPO and POD activities compared with the control. In addition, the Mn and Zn content in soya bean sprouts significantly increased, by approximately two- to threefold, compared with the control. This study provides a new method for improving the nutrient quality of soya bean sprouts based on postharvest Mn or Zn supplementation.