Establishment and analysis of the mRNA expression patterns of ABI3-like and storage protein genes during soybean seed development

Abstract

Abscisic acid insensitive 3 (ABI3) has a regulatory effect on the accumulation of storage proteins, as well as on the dormancy, quality, and drought tolerance of Arabidopsis seeds during development. The storage protein genes (SPGs) and relevant proteomics are already well understood; however, the mRNA expression patterns of the ABI3-like gene in soybean remain unknown. In this paper, the expression of ABI3-like and SPGs in soybean seeds was evaluated at the transcriptional level, which can provide a theoretical basis for soybean molecular breeding. Soybeans of the type 'NC111-1' were used as the qRT-PCR test material, in order to study the mRNA expression patterns of ABI3-like factors (GmABI3-8 and GmABI3-18), soybean SPGs (Gy1, Gy2, Gy3, Gy4, Gy5, Gy7, 7sa, 7sa', and 7sß), and their correlation. The results demonstrate that the mRNA expression patterns of GmABI3-8 and GmABI3-18 include bimodal curves, with the two peak periods corresponding to the filling and dehydration stages of soybean, respectively. The mRNA expression patterns of all SPGs exhibited single peak curves. 7sα, Gy1, and 7sß play major roles, and the expression level of 7sα was significantly higher than that of other SPGs (P<0.05). The expression levels of GmABI3-8 mRNA and each SPG (excluding Gy7) mRNA were significantly linearly correlated (P<0.05, r>0.8) in the filling stage, while GmABI3-18 mRNA was highly expressed during the dehydration stage. These new details about the specific transcription factors and regulatory roles of each storage protein, as well as the specific metabolic pathway of ABI3, show that GmABI3-8 and GmABI3-18 play an important role in the development of soybean seeds. This new data will help facilitate the development of molecular breeding methods for the production of new high-protein soybean varieties.