Overexpression of maize GOLDEN2 in rice and maize calli improves regeneration by activating chloroplast development  

作　　者：Wanni Luo Jiantao Tan Tie Li Ziting Feng Zhi Ding Xianrong Xie Yuanling Chen Letian Chen Yao-Guang Liu Qinlong Zhu Jinxing Guo 

机构地区：[1]State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources,College of Life Sciences,South China Agricultural University,SCAU,Guangzhou 510642,China [2]Guangdong Laboratory for Lingnan Modern Agriculture,Guangzhou 510642,China

出　　处：《Science China(Life Sciences)》2023年第2期340-349,共10页中国科学（生命科学英文版）

基　　金：supported by the Major Program of Guangdong Basic and Applied Research(2019B030302006);the Laboratory of Lingnan Modern Agriculture Project(NT2021002);the National Natural Science Foundation of China(31921004)。

摘　　要：Golden2(G2), a member of the GARP transcription factor superfamily, regulates several biological processes and phytohormone signaling pathways in plants. In this study, we used a rice codon-optimized maize G2 gene(rZmG2) to improve the regeneration efficiency of rice and maize calli for genetic transformation. We isolated a promoter driving strong and callus-specific expression from rice to drive rZmG2 transcription from a transgene after transformation of two indica and two japonica rice cultivars. The resulting rZmG2 transgenic calli turned green in advance at the differentiation stage, thus significantly raising the regeneration rates of the transgenic indica and japonica rice plants relative to control transformations. Similar effect of this gene on improving maize transformation was also observed. Transcriptome sequencing and RT-qPCR analyses showed that many rice genes related to chloroplast development and phytohormones are upregulated in rZmG2-transgenic calli. These results demonstrate that rZmG2 can promote embryogenic callus differentiation and improve regeneration efficiency by activating chloroplast development and phytohormone pathways. We also established a heat-inducible Cre/loxP-based gene-excision system to remove rZmG2 and the antibiotic selectable gene after obtaining the transgenic plants. This study provides a useful tool for functional genomics work and biotechnology in plants.

关 键 词：RICE ZmG2 genetic transformation callus regeneration CHLOROPLAST 

分 类 号：S513[农业科学—作物学]