Natural Variation in the Promoter of GmSPL9d Affects Branch Number in Soybean.

The branch number is a crucial factor that influences density tolerance and is closely associated with the yield of soybean. However, its molecular regulation mechanisms remain poorly understood. This study cloned a candidate gene GmSPL9d for regulating the soybean branch number based on the rice OsSPL14 homologous gene. Meanwhile, the genetic diversity of the GmSPL9d was analyzed using 3599 resequencing data and identified 55 SNP/InDel variations, which were categorized into seven haplotypes. Evolutionary analysis classified these haplotypes into two groups: GmSPL9d H-I and GmSPL9d H-II. Soybean varieties carrying the GmSPL9d H-II haplotype exhibited a significantly lower branch number compared with those carrying the GmSPL9d H-I haplotype. Association analysis between the variation sites and branch number phenotypes revealed a significant correlation between the promoter variations and the branch number. Promoter activity assays demonstrated that the GmSPL9d H-II promoter displayed significantly higher activity than the GmSPL9d H-I promoter. Transgenic experiments confirmed that the plants that carried the GmSPL9d H-II promoter exhibited a significantly lower branch number compared with those that carried the GmSPL9d H-I promoter. These findings indicate that the variation in the GmSPL9d promoter affected its transcription level, leading to differences in the soybean branch number. This study provides valuable molecular targets for improving the soybean plant structure.

The central role of GmGLP20.4 in root architecture modifications of soybean under low-nitrogen stress.

KEY MESSAGE: The GmGLP20.4 candidate gene plays an important role to improve soybean root architecture under low-nitrogen stress. The results lay the foundation for breeding low-nitrogen-tolerant soybean. Roots are fundamentally important for plant growth and development, facilitating water and nutrient uptake. Various abiotic and biotic factors significantly affect the root system architecture, especially low nitrogen (LN), but the molecular mechanism remains unclear. In this study, we identified GmGLP20.4, a germin-like protein (ubiquitous plant glycoproteins belonging to the Cupin superfamily) crucial for lateral root development and highly induced by LN stress in lateral roots of soybean. GmGLP20.4 overexpression increased root biomass through development of an improved root system in soybean under LN, whereas a significant decrease in root biomass was observed in the gmglp20.4 knockout mutant. Overexpression of GmGLP20.4 improved plant growth and root architecture in transgenic tobacco (Nicotiana tabacum) under LN. Natural variation of the GT-1 cis-element in the promoter (T to A) of GmGLP20.4 was strongly associated with its expression level under LN, and significantly increased LN-sensitive variation (type A) was observed in wild soybean compared to that in elite cultivars. Thus, type A variation in the promoter of GmGLP20.4 may have been a site of artificial selection during domestication. The GmGT1-16g gene was highly expressed under LN and showed an expression pattern opposite to that of GmGLP20.4. A luciferase complementation imaging assay revealed that the GmGLP20.4 promoter specifically binds to GmGT1-16g. In conclusion, GmGLP20.4 is involved in soybean root development and the natural variation of its promoter will be useful in modern intercropping systems or to improve nitrogen-use efficiency.

GmWRI1c Increases Palmitic Acid Content to Regulate Seed Oil Content and Nodulation in Soybean (Glycine max).

Soybean (Glycine max) is an important oil crop, but the regulatory mechanisms underlying seed oil accumulation remain unclear. We identified a member of the GmWRI1s transcription factor family, GmWRI1c, that is involved in regulating soybean oil content and nodulation. Overexpression of GmWRI1c in soybean hairy roots increased the expression of genes involved in glycolysis and de novo lipogenesis, the proportion of palmitic acid (16:0), and the number of root nodules. The effect of GmWRI1c in increasing the number of root nodules via regulating the proportion of palmitic acid was confirmed in a recombinant inbred line (RIL) population. GmWRI1c shows abundant sequence diversity and has likely undergone artificial selection during domestication. An association analysis revealed a correlation between seed oil content and five linked natural variations (Hap1/Hap2) in the GmWRI1c promoter region. Natural variations in the GmWRI1c promoter were strongly associated with the GmWRI1c transcript level, with higher GmWRI1c transcript levels in lines carrying GmWRI1cHap1 than in those carrying GmWRI1cHap2. The effects of GmWRI1c alleles on seed oil content were confirmed in natural and RIL populations. We identified a favourable GmWRI1c allele that can be used to breed new varieties with increased seed oil content and nodulation.

The construction of the indicators of professional competence for exercise instructors of the elderly.

The purpose of this study was to construct the quality indicators of professional competence for exercise instructors of the elderly, and then to rank the importance among those indicators. This study used the Delphi technique to integrate the opinions of 11 experts to construct the indicators, and then adopts the analytic hierarchy process (AHP) to calculate the relative rank among each individual indicator. Results revealed that the experts identified 3 first-degree indicators (professional attitude, professional skills, and professional knowledge), 10 second-degree indicators (teaching attitude, exercise knowledge, professional growth, exercise safety, personal characteristics, exercise instructor, gerontology knowledge, communicative competence, curriculum design, and motor skill), and 72 third-degree indicators. In the indicator weighting system, professional attitude was the most important among all other first-degree indicators, and the teaching attitude was the most important among all other second-degree indicators. The results provided will help in planning the curriculums of training, professional growth and evaluation. The results also provide a reference for future research.

The construction of the indicators of professional competence for exercise instructors of the elderly.

The purpose of this study was to construct the quality indicators of professional competence for exercise instructors of the elderly, and then to rank the importance among those indicators. This study used the Delphi technique to integrate the opinions of 11 experts to construct the indicators, and then adopts the analytic hierarchy process (AHP) to calculate the relative rank among each individual indicator. Results revealed that the experts identified 3 first-degree indicators (professional attitude, professional skills, and professional knowledge), 10 second-degree indicators (teaching attitude, exercise knowledge, professional growth, exercise safety, personal characteristics, exercise instructor, gerontology knowledge, communicative competence, curriculum design, and motor skill), and 72 third-degree indicators. In the indicator weighting system, professional attitude was the most important among all other first-degree indicators, and the teaching attitude was the most important among all other second-degree indicators. The results provided will help in planning the curriculums of training, professional growth and evaluation. The results also provide a reference for future research.