miR399a在番茄磷饥饿响应中的作用  

Function of miR399a in tomato in responding to phosphorus starvation

作　　者：李勤 黄健子 李紫薇 黄腾波 LI Qin;HUANG Jianzi;LI Ziwei;HUANG Tengbo(College of Life Sciences and Oceanography,Guangdong Provincial Key Laboratory for Plant Epigenetics,Shenzhen University,Shenzhen 518071,Guangdong Province,P.R.China)

机构地区：[1]深圳大学生命与海洋科学学院,广东省植物表观遗传重点实验室,广东深圳518071

出　　处：《深圳大学学报（理工版）》2023年第4期415-424,共10页Journal of Shenzhen University(Science and Engineering)

基　　金：广东特支计划科技创新青年拔尖人才资助项目(2019TQ05N940);深圳市高等院校稳定支持计划资助项目(20200813135146001);深圳市基础研究计划资助项目(JCYJ20220531101218040)。

摘　　要：磷饥饿胁迫可引起植物生长缓慢进而影响产量.作为植物中参与磷饥饿响应的关键微小核糖核酸(micro ribonucleic acid,microRNA),microRNA399(miR399)在番茄(Solanum lycopersicum)中的功能及作用机制尚待阐明.通过在不同浓度磷水平下培养野生型和过表达miR399a番茄株系,测定各植株根长、侧根数量和根冠比等形态指标,分析各植株中Sly-miR399a和phosphate 2(PHO2)的基因表达量,并检测各植株中无机磷含量、叶绿素和花青素含量、紫色酸性磷酸酶以及过氧化物酶活性等生理指标.结果表明,相较于野生型株系,过表达番茄株系中的Sly-miR399a表达水平显著升高,而PHO2表达水平显著下调;在低磷浓度培养下,野生型和过表达Sly-miR399a番茄植株主根均显著变长,且侧根数量显著增加;而无论磷浓度高低,过表达Sly-miR399a番茄株系植株根长均增加;过表达Sly-miR399a还可以促进植株体内无机磷积累,并引起番茄叶片中叶绿素和花青素含量增加,番茄植株紫色酸性磷酸酶和过氧化物酶活性增强.研究验证了miR399a在番茄中参与磷饥饿胁迫响应,揭示miR399的功能在植物中具有保守性.Phosphorus starvation may cause retarded plant growth and subsequently affect plant yield.As a key microRNA involved in plant response to phosphorus starvation,the function and regulatory mechanism of microRNA399(miR399)in tomatoes(Solanum lycopersicum)remains to be elucidated.By cultivating wild type(WT)and Sly-miR399a-overexpressing(amiR399a)tomato plants under different phosphorus concentrations,the morphological indicators including root length,lateral root number,and root shoot ratio were measured for each sample.At the same time,the relative expression levels of Sly-miR399a and phosphate 2(PHO2)gene,the contents of inorganic phosphorus,the contents of anthocyanin and chlorophyll,the activity of purple acid phosphatase and peroxidase were also determined for each sample.The results show that the expression levels of Sly-miR399a are significantly up-regulated in amiR399a plants relative to WT plants,while the expression levels of PHO2 are significantly down-regulated in amiR399a plants.Under low-concentration-phosphorus cultivation,the length of main root and the number of lateral roots significantly increase in both WT and amiR399a plants.Either in normal or low concentration phosphorus condition,overexpression of Sly-miR399a in tomato plants can promote the root elongation.In addition,overexpression of Sly-miR399a can also contribute to the accumulation of inorganic phosphorus in tomato plants,and induce the increase of chlorophyll and anthocyanin contents in tomato leaves,and increase purple acid phosphatase and peroxidase activity in tomato.This study verifies the participant of Sly-miR399a in phosphorus starvation response in tomato,and reveals that the function of miR399 might be conserved in plants.

关 键 词：植物生理学 番茄 磷饥饿胁迫 Sly-miR399a 基因表达 钼锑抗法 花青素 叶绿素 紫色酸性磷酸酶 过氧化物酶 

分 类 号：Q945.78[生物学—植物学]