Phytochrome-interacting factors (PIFs) play a crucial role in regulating plant growth and development. However, studies on soybean PIFs are limited. Here, we identified 22 GmPIF genes from the soybean genome and classified the GmPIF proteins into 13 subfamilies based on amino acid sequence homology, secondary and tertiary structures, protein structure, and conserved motifs. Genome-wide collinearity analysis revealed that fragment duplication events play a dominant role in expanding the GmPIF gene family. Cis-acting element analysis revealed that the GmPIF gene family is involved in light response, hormone response, biotic-abiotic stress response elements, and plant growth and development. Gene expression analysis in different temperature environments showed that the GmPIF family was found to be induced by phytohormone treatments, with a significant increase in the expression level of GmPIF3g. GmPIF3g plays a key role in the regulation of the entire network, and in addition, 30 proteins interacting with the GmPIF3g promoter were identified through the use of a novel biofilm interference technique. This technique showed that the transcription factor Dof (DNA binding with one finger) binds to the GmPIF3g promoter, and Y1H assays indicated that Dof regulates its expression by binding to the PIF promoter. These results provide a theoretical basis for further studies on the regulatory network of GmPIF genes to improve the structure of soybean plants under shade environments, as well as a new method for analyzing regulatory elements that interact with gene promoters.

The male sterile line of soybean is crucial for hybrid seed production, and has allowed significant advancements in soybean germplasm innovation and yield increase in China. In this study, we created two bulks of sterile plants and collected a natural population consisting of 100 elite soybean germplasms. There were significant phenotypic differences between the sterile and natural populations resulting from flowers and pods. The sterile plants exhibited fleshy spherical pods and large black-green leaves in the maturity stage, while the leaves of the fertile plants fell off. After I2-KI staining, the pollen of the sterile line turned light brown and yellow, while the pollen of the fertile line turned black. On the basis of the SNP sequencing results, the sterility genes were located on eight chromosomes. Additionally, they were fine-mapped to 13 regions on six chromosomes using 72 pairs of SSR markers. Five genes involved in auxin response and pollen development were predicted as candidate genes underlying soybean sterility. These candidate genes for soybean sterility will help with gene cloning and functional analysis and accelerate the widespread use of hybrid seed production and yield increase in soybean grown in cool regions.

Lodging of soybean (Glycine max (L.) Merril.) significantly reduces seed yield and quality, particularly in high-yielding environments. This phenomenon occurs when stems weaken under the weight of the plants, complicating harvesting. This study investigated the relationship between soybean stem chemical composition, physical traits, and lodging resistance to improve yield and resilience. We found that as plant density increased, stem hardness decreased, and the elasticity increased, heightening the risk of lodging. Conversely, high temperature (28 °C) boosted lignin, cellulose and pectin content in the stem cell walls, enhancing the lodging resistance. Additionally, after excluding differences in phylogenetic relationships through cluster analysis, we mapped environment-stable genes linked to lodging resistance and identified new QTLs on Chr3 and Chr16. Candidate genes associated with these QTLs were confirmed using qRT–PCR and hormone treatments across diverse soybean varieties. It was found that the expression of stem tip genes was closely related to stem node diameter. These findings provide a theoretical foundation for breeding high-yielding soybean varieties with improved lodging resistance, and advance efforts to develop resilient soybean cultivars.

The plant rhizosphere underlies the crosstalk between plant and soil and has a crucial role in plant growth and development under various environments. We examined the effect of temperature rise on the rhizosphere environment of soybean roots to clarify the rhizosphere crosstalk between roots and soil in response to warm temperature rises in a global warming background. The in situ results of root enzyme activity revealed that soybean roots secrete β-glucosidase, and enzyme spectrum imaging demonstrated different enzymatic activities under different temperature environments. The soil enzyme kinetics results showed that soil enzymatic activity increased with increasing temperature, and soybean rhizosphere soil enzymatic activity was higher than that of non-rhizosphere soil. Rhizosphere soil and non-rhizosphere soil showed that the dominant bacterial phylum in soybean rhizosphere soil was Acidobacteria, and the dominant bacterial genus was JG30-KF-AS9. Compared with non-rhizosphere soil, rhizosphere soil was more nutrient-rich, and root secretions provided abundant carbon sources and other nutrients for soil microorganisms in the rhizosphere. Rhizosphere microorganisms affect plant growth by influencing the decomposition of soil organic carbon. The organic carbon content of rhizosphere soil was higher than that of non-rhizosphere soil under high temperatures.

为了解大豆节间在不同温度和外源赤霉素(gibberellic acid,GA)诱导条件下的表型变化规律,分析GA合成重要途径和挖掘调控节间的关键候选基因,本研究将大豆品种Charleston在培养箱条件和室外盆栽条件种植,进行不同温度处理和外源GA涂抹处理,利用徒手切片配合显微照相方法,分析大豆节间长度和细胞形态变化;利用液相色谱-质谱联机结合转录组测序方法分析大豆节间GA合成主要通路并挖掘调控节间生长的关键候选基因.结果表明在25℃和30℃条件下,外源涂抹不同浓度GA可以诱导大豆生长节间伸长,随着伸长量的增加,大豆节间都变得纤细.外源GA对细胞作用效果主要为促进伸长,对宽度影响不明显.高温处理对节间的伸长效果高于低温处理.本研究鉴定到GA2氧化酶基因在大豆生长节间表达和较高含量的GA19和GA53,及这2种GA下游的GA20(活性GA前体),以及这条合成途径的活性GA产物GA3也被检测到都存在于细胞伸长区组织,说明从GA前体物质到GA53,再到GA19,通过GA20最终合成GA3是大豆节间生长的一条重要GA合成通路,进一步说明GA2氧化酶在大豆节间生长过程中有重要作用.挖掘到某些DELLA、GA和PIF基因家族成员具有组织表达特异性,为调节大豆节间和株高提供了候选基因.

为明确大豆节间木质素积累规律,深入理解木质素积累与大豆植株抗倒伏间的关系,进而为调控大豆植株表型和抗倒伏大豆新品种选育提供参考依据,选取具有代表性的有限生长习性品种Charleston,按照20,35株/m2的2种密度种植桶栽大豆,在2种不同密度下测定主茎的木质素含量,分析Charleston主茎第3节间的细胞伸长区(EZ)和次生细胞壁成熟区(MZ)木质素含量、在木质素合成过程中的4-香豆酸:辅酶A连接酶(4CL)、苯丙氨酸转氨酶(PAL)、肉桂酸脱氢酶(CAD)等关键酶活性以及对应基因的表达量.手工切片及分光光度计测定的结果表明,大豆主茎木质素含量由形态学上端向下端逐渐增加.低密度处理主茎中的木质素含量高于高密度.无论是高密度还是低密度处理,单一节间(茎3)木质素含量均为MZ>EZ;低密度处理茎中4CL、PAL、CAD的活性高于高密度处理.2个密度处理下茎中4CL、PAL、CAD活性变化规律较为一致,与基因表达结果相符合.大豆植株主茎中木质素含量受到木质素合成途径中的多种酶调控.木质素合成的关键酶基因多以基因家族形式存在,同一基因家族中的酶基因在同一物种植株的相同部位表达存在差异,同一基因在同一物种的不同组织和器官中的表达情况也不尽相同.

选取不同生长习性大豆品种DN50、DN594和Charleston,按照20、35株·m-2两种密度盆栽种植,植株生长期间每天测量株高,利用Excel 2010软件统计并分析株高数据,Logistic回归分析建立不同生长习性大豆不同密度处理条件下生长规律模型,明确不同生长习性大豆生长规律.结果表明,高密度与低密度处理的大豆品种主茎生长发育规律一致,呈"慢-快-慢"S形曲线,前慢期持续时间长于后慢期,不同密度植株最大生长速率出现在同一时段.两种密度条件下株高发育曲线在生长发育前期几乎完全重合,而发育后期曲线分离,株高差异明显.因生长习性不同,不同品种株高生长速率曲线存在差异.不同生长习性大豆品种Logistic解析式曲线预测株高最大值差异明显,但3个品种不同密度处理下模型曲线均为"S"型,拟合情况良好,可为大豆田间管理和高产株型育种提供理论支持.