Transcription factors NAC20 and NAC26 interact with RPBF to activate albumin accumulations in rice endosperm

作者：Ming‐Wei Wu, Jinxin Liu, Xue Bai, Wen‐Qiang Chen, Yulong Ren, Jin‐Lei Liu, Mengmeng Chen, Heng Zhao, Xuefeng Yao, Jindan Zhang, Jianmin Wan, Chunming Liu · 发表于：Plant Biotechnology Journal · 年份：2022 · DOI：10.1111/pbi.13994 · 被引用次数：18 · 研究领域：Food composition and properties、Biofuel production and bioconversion

Storage proteins (SPs) and starch deposited in cereal endosperms are the most important sources of human food. SPs are classified into glutelins, prolamins, albumins and globulins according to their solubility in various solvents (Müntz, 1998). Most of these proteins are encoded by multiple genes and deposited specifically in endosperms through the regulation of transcription factors (TFs) (Liu et al., 2022). Among them, albumin is the most abundant water-soluble protein (Müntz, 1998), and the most important allergenic protein in the rice endosperm (Matsuda et al., 1991). Thus, understanding molecular machinery underlying albumin accumulations is critically important. In maize, NAC TFs, NAC128/130, regulate starch and SP accumulations (Zhang et al., 2019). NAC20 and NAC26 (NAC20/26 hereafter) are specifically expressed in developing rice endosperm, and mutations of both genes led to floury endosperm, together with compromised accumulations of starch and SP (Wang et al., 2020). In this study, a NAC20/26 double knockout mutant, named nac20/26-3, was generated in a Japonica rice variety Zhonghua 11 (ZH11; Figure S1), which exhibited similar floury endosperm phenotype as reported (Wang et al., 2020; Figure S2). SDS-PAGE analyses of total proteins extracted from mature nac20/26-3 endosperms showed that a 16-kDa band was disappeared, and a 26-kDa band was attenuated greatly when compared with ZH11 (Figure 1a). Previous studies suggest that the former is prolamin, and the latter is ...