Evolutionary research on the expansin protein family during the plant transition to land provides new insights into the development of Tartary buckwheat fruit

Abstract

Background Plant transitions to land require robust cell walls for regulatory adaptations and to resist changing environments. Cell walls provide essential plasticity for plant cell division and defense, which are often conferred by the expansin superfamily with cell wall-loosening functions. However, the evolutionary mechanisms of expansin during plant terrestrialization are unclear. Results Here, we identified 323 expansin proteins in 12 genomes from algae to angiosperms. Phylogenetic evolutionary, structural, motif gain and loss and Ka/Ks analyses indicated that highly conserved expansin proteins were already present in algae and expanded and purified after plant terrestrialization. We found that the expansion of the FtEXPA subfamily was caused by duplication events and that the functions of certain duplicated genes may have differentiated. More importantly, we generated space-time expression profiles and finally identified five differentially expressed FtEXPs in both large and small fruit Tartary buckwheat that may regulate fruit size by responding to indoleacetic acid. Conclusions A total of 323 expansin proteins from 12 representative plants were identified in our study during terrestrialization, and the expansin family that originated from algae expanded rapidly after the plants landed. The EXPA subfamily has more members and conservative evolution in angiosperms. FtEXPA1, FtEXPA11, FtEXPA12, FtEXPA19 and FtEXPA24 can respond to indole-3-acetic acid (IAA) signals and regulate fruit development. Our study provides a blueprint for improving the agronomic traits of Tartary buckwheat and a reference for defining the evolutionary history of the expansin family during plant transitions to land.

Dynamic transcriptome analysis suggests the key genes regulating seed development and filling in Tartary buckwheat (Fagopyrum tataricum Garetn.)

“…Nevertheless, FtEXPA5 , FtEXPA15 , FtEXPA21 , FtEXPA27 , FtEXPA28 , FtEXPA29 and FtEXPB4 displayed the most significant transcriptional variations along with the seed growth ( Figure 9A ). Interestingly, these genes were phylogenetically quite close, as FtEXPA5, FtEXPA28 , FtEXPA29 and FtEXPA27 were classified in the same branch in the previous report ( Sun et al, 2021 ).…”

Overexpression of AcEXPA23 Promotes Lateral Root Development in Kiwifruit

“…The expansin gene is widespread in plants, ranging from algae to higher plants, indicating that the expansin protein family is important for the growth and development of plants [ 40 ]. Evolutionary analysis of expansins can provide valuable insights into the regulation of important agronomic traits in kiwifruit genetics and breeding.…”

Genome-wide identification of MAPK gene family members in Fagopyrum tataricum and their expression during development and stress responses

“…The qRT–PCR primers (Additional file 5 ) were designed via primer 3 ( https://www.ncbi.nlm.nih.gov/tools/primer-blast/ ). Refer to Liu et al [ 56 ] for the selection of the internal reference genes. 2xChamQ Universal SYBR qPCR Master Mix (Vazyme, China) was used for qRT–PCR.…”