Plant roots play crucial roles in their response to drought conditions. However, the molecular responses in soybean roots to drought stress remain unclear. We investigated the alterations in the protein expression in the roots of a drought-resistant soybean cultivar ‘Jiyu 47’ during the seedling phase based on tandem mass tag (TMT) proteomics analysis. The results revealed significant variations in the expression of the proteins involved in several metabolic pathways in soybean roots, including sucrose metabolism, abscisic acid (ABA) metabolism, and the ATP-binding cassette (ABC) transporter pathway. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses revealed a coordinated expression pattern of the proteins involved in the various cellular pathways responding to drought stress in soybean. The increased production of sucrose and betaine enhanced the inhibition of the damage caused by reactive oxygen species (ROS) and the tolerance of drought stress. The results of the physiological variations showed that sucrose metabolism, ABA metabolic mechanism, and the ABC transporter pathways played an important role in the antioxidant defense system in response to drought stress in soybean roots. The results of quantitative real-time PCR revealed the up-regulated expression of three genes (i.e., GmPYR1, GmHO-1, and GmSOD) involved in ABA biosynthesis and the signaling pathway. This study provides novel insights into the comprehension of the molecular pathways regulating the soybean root response to drought stress.

NAC transcription factors are commonly involved in the plant response to drought stress. A transcriptome analysis of root samples of the soybean variety ‘Jiyu47’ under drought stress revealed the evidently up-regulated expression of GmNAC19, consistent with the expression pattern revealed by quantitative real-time PCR analysis. The overexpression of GmNAC19 enhanced drought tolerance in Saccharomyces cerevisiae INVSc1. The seed germination percentage and root growth of transgenic Arabidopsis thaliana were improved in comparison with those of the wild type, while the transgenic soybean composite line showed improved chlorophyll content. The altered contents of physiological and biochemical indices (i.e., soluble protein, soluble sugar, proline, and malondialdehyde) related to drought stress and the activities of three antioxidant enzymes (i.e., superoxide dismutase, peroxidase, and catalase) revealed enhanced drought tolerance in both transgenic Arabidopsis and soybean. The expressions of three genes (i.e., P5CS, OAT, and P5CR) involved in proline synthesis were decreased in the transgenic soybean hairy roots, while the expression of ProDH involved in the breakdown of proline was increased. This study revealed the molecular mechanisms underlying drought tolerance enhanced by GmNAC19 via regulation of the contents of soluble protein and soluble sugar and the activities of antioxidant enzymes, providing a candidate gene for the molecular breeding of drought-tolerant crop plants.

【Objective】The aim of this study was to pave the way for the construction of high-density genetic map and QTL (quantitative trait locus) analysis, so as to facilitate the parental selection and mating design in the breeding programs targeting for new varieties in Chinese cherry (Cerasus pseudocerasus (Lindl.) G.Don) by investigating and analyzing fruit traits of F1 progenies between Nanzaohong (NZH, early maturity, orange red) and Hongfei (HF, purple red, with good comprehensive characteristics).【Method】The heredity variation and inheritance tendency of 17 fruit quality traits in the F1 segregating populations (n=226) were investigated, which were derived from the reciprocal cross between NZH and HF These traits included fruit weight, longitudinal, transverse and lateral diameter, total soluble solids (TSS), soluble sugar (SS), titratable acid (TA), anthocyanin content, fruit shape index, fruit development period, and fruit stalk length, etc.【Result】The average fruit weight in offspring of both NZH × HF (4.30 g; range: 2.59-7.46 g) and HF × NZH (4.05 g; range: 2.45-6.48 g) was smaller than the mid-parent value (4.58 g). The TSS content (14.55% and 14.51%) was higher than those of two parents (12.97% and 11.36%), and the ratio of individuals with TSS content higher than high parent（HH）was 78.52% and 76.09%. The average TA content of individuals from the reciprocal cross was lower than the low parent (LL) (47.92% and 41.94%). Peel color segregated in the F1 progenies, with orange red, red, purple red and black purple being observed. Hybrids with red fruit color accounted for the largest proportion. The anthocyanin content is in the range of 3.12-112.51 and 1.80-79.94 mg/kg. The average fruit development period of NZH × HF progenies was two days shorter than that of HF × NZH progenies, which was mainly affected by the male parent. The fruit stalk length showed heterosis with HH values of 49.25% and 43.33%, respectively. The mixed major gene and polygene inheritance model method was evaluated for their fitness relating to these traits. Two major genes plus polygenes model was the optimal genetic model for 11 (out of 12) quantitative traits except for the fruit longitudinal diameter, which was controlled by one major gene plus polygenes.【Conclusion】The main fruit quality characteristics were quantitative traits controlled by polygenic loci. The inheritance trend of the fruit weight, longitudinal, transverse, lateral diameter, TA, and anthocyanin content tended to be decreased, while the TSS, SS content and fruit stalk length tended to be increased.

Chinese cherry [Cerasus pseudocerasus (Lindl.) G.Don] is one of the important stone fruits in China. To explore the heredity variation of fruit-related traits, we investigated 18 fruit-related traits of the F-1 segregating population around 700 individuals derived from 'Hongfei' x 'Pujianghonghua' of Chinese cherry for two years. The mixed major gene and polygene inheritance model method was also evaluated for their fitness in relating to the traits. The results showed that the main fruit traits had different degrees of variation, with the coefficient of variation ranging from 4.76 to 26.71% (72.23% for anthocyanin content) in 2021, and from 4.71 to 21.57% in 2022. Significant levels of transgressive heterosis were observed for fruit stalk length, total soluble solid and anthocyanin content, whereas negative heterosis was detected in fruit weight and size. The most suitable genetic model for fruit maturity date and fruit development period was 2MG-ADI and 2MG-AD, respectively, and the heritability of major gene was greater than 90%. The optimal genetic model for ten fruit size and flavor related traits was 2MG-AD or 2MG-EA, which were controlled by two pairs of major genes with additive-dominant effect or equal-additive effect, with the major gene heritability being less than 45%. The additive effects of the fruit -related traits were mostly positive, while the dominant effects were mainly negative. These results provide a theoretical basis for quantitative trait locus (QTL) mapping and marker-assisted breeding of fruit-related traits in Chinese cherry.

Roots are generally the critical drought sensors, but little is known about their molecular response to drought stress. We used the drought-tolerant soybean variety 'Jiyu 47' to investigate the differentially expressed proteins (DEPs) in soybean roots during the seedling stage based on the tandem mass tag (TMT) proteomics analysis. Various expression patterns were observed in a total of six physiological parameters. A total of 468 DEPs (144 up-regulated and 324 down-regulated) among a total of 8687 proteins were identified in response to drought stress in 24 h. The expression of DEPs was further validated based on quantitative real-time PCR of a total of five genes (i.e., GmGSH, GmGST1, GmGST2 k GmCAT, and Gm6PGD) involved in the glutathione biosynthesis. Results of enrichment analyses revealed a coordinated expression pattern of proteins involved in various cellular metabolisms responding to drought stress in soybean roots. Our results showed that drought stress caused significant alterations in the expression of proteins involved in several metabolic pathways in soybean roots, including carbohydrate metabolism, metabolism of the osmotic regulation substances, and antioxidant defense system (i.e., the glutathione metabolism). Increased production of reduced glutathione (GSH) enhanced the prevention of the damage caused by reactive oxygen species and the tolerance of the abiotic stress. The glutathione metabolism played a key role in modifying the antioxidant defense system in response to drought stress in soybean roots. Our proteomic study suggested that the soybean plants responded to drought stress by coordinating their protein expression during the vegetative stage, providing novel insights into the molecular mechanisms regulating the response to abiotic stress in plants.

Soybean transcription factor GmNAC plays important roles in plant resistance to environmental stresses. In this study, GmNAC3 was cloned in the drought tolerant soybean variety “Jiyu47”, with the molecular properties of GmNAC3 characterized to establish its candidacy as a NAC transcription factor. The yeast self-activation experiments revealed the transcriptional activation activity of GmNAC3, which was localized in the nucleus by the subcellular localization analysis. The highest expression of GmNAC3 was detected in roots in the podding stage of soybean, and in roots of soybean seedlings treated with 20% PEG6000 for 12 h, which was 16 times higher compared with the control. In the transgenic soybean hairy roots obtained by the Agrobacterium-mediated method treated with 20% PEG6000 for 12 h, the activities of superoxide dismutase, peroxidase, and catalase and the content of proline were increased, the malondialdehyde content was decreased, and the expressions of stress resistance-related genes (i.e., APX2, LEA14, 6PGDH, and P5CS) were up-regulated. These expression patterns were confirmed by transgenic Arabidopsis thaliana with the overexpression of GmNAC3. This study provided strong scientific evidence to support further investigation of the regulatory function of GmNAC3 in plant drought resistance and the molecular mechanisms regulating the plant response to environmental stresses.

Phospholipid N-methyltransferase (PLMT) plays an important role in the synthesis of phosphatidylcholine (PtdCho). The aim of this study was to characterize the molecular properties of GmPLMT and the expression of soybean GmPLMT and its effects on the production of lipid metabolites. Results showed that GmPLMT composed of mainly α-helix was a hydrophobic and transmembrane protein. In soybean leaves, GmPLMT was highly expressed during seedling and flowering stages. In transgenic Arabidopsis thaliana, the highest and lowest expression levels of GmPLMT were detected at flowering and maturity stages, respectively. The total phospholipid contents in soybean grains were decreased from 7.2% (35 days after flowering) to 4.8% (55 days after flowering) and then increased to 7.0% (75 days after flowering). The contents of PtdCho showed a similar pattern to that of total phospholipids. In transgenic A. thaliana seeds, the contents of total phospholipids and PtdCho were significantly increased. Significantly positive correlations were revealed between expression of GmPLMT and contents of both PtdCho and crude fats, and between the contents of PtdCho and both linoleic acid and linolenic acid, suggesting that increased expression of GmPLMT improved the production of lipid metabolites. This study provided solid experimental evidence for further improvement of soybean quality based on GmPLMT in the molecular breeding of soybeans.

Phenylalanine ammonia-lyase (PAL), polyphenol oxidase (PPO), and peroxidase (POD) are considered important biochemical markers in host plant resistance against pest insects. Constitutive activity of these enzymes was analyzed in resistant and susceptible wheat cultivars against cereal aphid Sitobion avenae (F.) at various developmental stages, i.e., tillering, stem elongation, flag leaf, and ear. Following aphid infestation, the activity of these enzymes was determined at the flag leaf and ear stages. Resistant cultivars exhibited greater constitutive PAL activity than susceptible ones at the tillering, stem elongation, and flag leaf stages. Aphid infestation enhanced levels of PAL activity in the flag leaf and ear stages in both resistant and susceptible cultivars. Constitutive PPO activity was higher in the resistant cultivars at all developmental stages. Aphid infestation induced increases in PPO activity in the flag leaf and ear stages of one susceptible cultivar, whereas induction in resistant cultivars was weaker. Resistant cultivars showed greater constitutive POD activity in the tillering, stem elongation, and flag leaf stages, while aphid infestation induced POD activity in all cultivars, especially in susceptible ones. The potential role of PAL, PPO, and POD in wheat defense against aphid infestation is discussed.

Host plant resistance can effectively reduce pest insect populations, but a concern is whether plant resistance could also negatively affect the natural enemies of the insect pests. In this paper the effect of three wheat cultivars on the population of an aphid species, Sitobion avenae (F.) and it’s parasitoids, Aphidius spp., were investigated in the field experiments in 2004 and 2005. Percentage of parasitized aphids at peak sampling date was also recorded. Both the aphid and parasitoid populations varied in the three wheat cultivars at the sampling dates. The density peak of parasitoid population in all the three wheat cultivars was 9–12 days behind the density peak of the aphid population. At the population peaks both the aphid and parasitoid densities were significantly higher in the susceptible than in the resistant cultivars. Furthermore, the accumulative parasitism was significantly higher in the resistant than in the susceptible cultivar, and level of resistance of the wheat cultivars had no effect on aphid mummy weight parasitized by A. spp. These results suggested that the host plant resistance against aphids enhanced the parasitism of aphid species S. avenae (F.) by its parasitoid A. spp. in wheat field.

Two Sitobion avenae-resistant (KOK1679 and Li) and two S. avenae-susceptible (Beijing 837 and Beijing 411) wheat varieties were planted in net-house at Science Garden, China Agricultural University, and the contents of p-hydroxybenzoic acid, caffeic acid and ferulic acid from diffferent S. avenae-resistant wheat varieties were determined by HPLC in different tissues of wheat plants. The results showed that the content of ferulic acid in aphid-resistant wheat varieties was signif icantly higher than that in aphid-susceptible ones in all tested tissues. Conversely, the content of caffeic acid at seedling stage and in flag leaves of aphid-susceptible varieties was signifi cantly higher than that in aphid-resistant ones, as well as the content of p-hydroxybenzoic acid in the ear. On the other hand, except for the content of p-hydroxybenzoic acid in KOK1679, the contents of all the three phenolic acid compounds among growing stages or tissues were significantly different in a given variety. Therefore, these results suggested that ferulic acid content in wheat tissues could be related to wheat resistance to aphid. Fig 2, Tab 1, Ref 21