Min Zhang, Shulin Liu, Zhao Wang, Yaqin Yuan, Zhifang Zhang, Qianjin Liang, Xia Yang, Zongbiao Duan, Yucheng Liu, Fanjiang Kong, Baohui Liu, Bo Ren, Zhixi Tian

Plant Biotechnol J.; 2022 Feb; 20(2):256-282. doi: 10.1111/pbi.13682. 

Abstract

Soybean is one of the most important oilseed and fodder crops. Benefiting from the efforts of soybean breeders and the development of breeding technology, large number of germplasm has been generated over the last 100 years. Nevertheless, soybean breeding needs to be accelerated to meet the needs of a growing world population, to promote sustainable agriculture and to address future environmental changes. The acceleration is highly reliant on the discoveries in gene functional studies. The release of the reference soybean genome in 2010 has significantly facilitated the advance in soybean functional genomics. Here, we review the research progress in soybean omics (genomics, transcriptomics, epigenomics and proteomics), germplasm development (germplasm resources and databases), gene discovery (genes that are responsible for important soybean traits including yield, flowering and maturity, seed quality, stress resistance, nodulation and domestication) and transformation technology during the past decade. At the end, we also briefly discuss current challenges and future directions.

See: https://pubmed.ncbi.nlm.nih.gov/34388296/

Figure 2: Proposed molecular regulation network of flowering in soybean. Soybean is a short‐day flowering plant. E3 and E4 mediate flowering by responding to the ratios of red (R) and far‐red (FR) light. Under long days (LDs), E3 and E4 induce the expression of E1. GmTof11 and GmTof12 inhibit the expression of GmLHYs by binding to their promoters. GmLHY proteins directly bind to the promoter region of J to induce its expression and bind to the promoter of E1 to suppress its transcription. LUX can physically interact with GmELF3a/b to repress E1 expression. E1 inhibits the expression of the flowering‐inducing factors GmFT2a and GmFT5a. This suppresses the expression of floral identity genes (GmAP1, GmSOC1s, GmLFYs, GmFULs). As a result, flowering is delayed under LDs. Under SDs, the induction of E1 is decreased, which releases the transcriptional suppression of GmFT2a and GmFT5a, promoting flowering. The E2 and miRNA‐dependent flowering regulation modules are also influenced by photoperiod under PHYA mediation (E3 and E4). GmCOL1a/1b and GmTOE4a inhibit flowering via down‐regulation of GmFT2a and GmFT5a expression. GmTOE4a expression is possibly controlled by miR172, which is under the control of miR156b. miR156b may delay flowering by negatively regulating the GmSPLs.