《植物生理学报》 2021, 57(6): 1199-1210

水稻OsANT亚家族成员的结构、表达特征及其对逆境胁 迫的响应

谢君¹，徐智军¹，蔺金红¹，曾庆平¹，赵静^2,*，刘伯涵^1,3，叶能辉^1,3，孟栓^1,3,*

¹湖南农业大学农学院, 长沙410128；²湖南农业大学生物科学技术学院, 长沙410128；³水稻逆境生物学湖南省重点实验室, 长沙410128

通信作者：赵静；E-mail: zhj88717@live.cn；孟栓；E-mail: mengshuan1987@126.com

摘　要：

植物氨基酸转运蛋白直接负责氨基酸的跨膜转运过程, 分属于3个家族的不同亚家族, 其中ANT亚 家族成员主要负责芳香族氨基酸和中性氨基酸的转运。本文对水稻ANT亚家族成员的系统进化树、跨 膜结构和蛋白保守基序特征进行了分析, 对成员的时空表达特征和逆境下的响应情况进行了研究, 并利 用氨基酸吸收缺陷型酵母分析了OsANT的氨基酸吸收特性。结果表明, OsANT亚家族的4个成员在进化 上与单子叶植物玉米和高粱的关系较近, 而与双子叶植物拟南芥和番茄的关系较远; 蛋白保守基序特征 分析表明, OsANT亚家族成员与其他物种中的ANT成员有6个共有的保守基序; 基因表达分析表明,  OsANT亚家族基因在不同组织和部位之间具有差异性表达的特征, 可能协同参与了水稻体内氨基酸的利 用过程; 逆境下基因表达量的分析表明, OsANT亚家族基因可能参与到多种逆境的响应过程中, 其中 OsANT1 (根部)对热胁迫、OsANT2对氮素营养水平、OsANT3 (地上部)对盐胁迫以及OsANT4 (根部)对镉 胁迫响应较为明显; 然而, 利用氨基酸吸收缺陷型酵母的互补实验表明, OsANT亚家族成员对多种氨基酸 均无明显的吸收活性。该研究对于解析OsANT亚家族成员的功能以及逆境下氨基酸转运分配的机制提 供了重要的线索和基础。

关键词：水稻(Oryza sativa); OsANT; 氮素; 逆境胁迫; 基因表达

资助：国家自然科学基金(31900219)、湖南省教育厅科学研究项目(19B273和19C0898)和湖南农业大学青年基金(18QN18和18QN28)

Structure characterization, expression and stress response analyses of  OsANT subfamily genes in rice

XIE Jun¹, XU Zhijun¹, LIN Jinhong¹, ZENG Qingping¹, ZHAO Jing^2,*, LIU Bohan^1,3, YE Nenghui^1,3, MENG Shuan^1,3,*

¹College of Agronomy, Hunan Agricultural University, Changsha 410128, China; ²College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha 410128, China; ³Hunan Provincial Key Laboratory of Rice Stress Biology, Changsha 410128, China

Corresponding author: ZHAO Jing; E-mail: zhj88717@live.cn; MENG Shuan; E-mail: mengshuan1987@126.com

Abstract:

Amino acid transporters are directly responsible for the transmembrane transport of amino acids within plants, and they belong to different subfamilies of three major families. The ANT subfamily  members are mainly responsible for the transport of aromatic and neutral amino acids. This research focuses  on the phylogenetic tree, structure characterization, expression and stress response of OsANT subfamily  genes. The amino acid absorption characteristics of OsANT subfamily members are also analyzed. The  results showed that OsANT display a closer evolutionary relationship to the ANT members from monocotyledon such as Zea mays and Sorghum bicolor than to the ANT members from dicotyledonous plants such as  Arabidopsis thaliana and Lycopersicon esculentum. Conserved motifs analysis using MEME tool identified six  conserved motifs among ANT proteins of rice and other species. Gene expression analysis showed that four  OsANT genes were differentially expressed among different tissues and organs, which implied that they  might work together for utilizing amino acids within rice plants. Further analysis found that OsANT subfamily  genes might involve in adversity stresses response, as the expression level of OsANT1 in roots was effectively  affected by heat stress, expression level of OsANT2 changed by nitrogen treatment, salt induced OsANT3 expression in shoots and cadmium stress induced OsANT4 expression in roots, respectively. However, all  OsANT subfamily members failed to show any transport activity for the tested amino acid in heterologous  complementation experiments using a yeast amino acid transporter mutant. This study provides valuable  clues for further uncover the biological and physiological functions of OsANT members, and will be also  helpful for researching on the mechanisms of transport and distribution of amino acids under stresses.

Key words: rice (Oryza sativa); OsANT; nitrogen; stress; gene expression