玉米ZmNLP 5与ZmSTP 1、ZmAAP 2基因启动子区域相互作用的鉴定

Identification of the interaction between ZmNLP5 and promoters of ZmSTP1,ZmAAP2 gene in maize

氮(N)是控制玉米产量的主要限制性因素,玉米对氮素的利用效率可以通过增加碳(C)的有效性得以改善。玉米转运蛋白ZmSTP1和ZmAAP2在植物C/N产物的运输和卸载过程中起着重要作用,且两个基因的启动子区域均含有一个硝酸盐响应顺式元件(nitrate responsive cis element,NRE)。NIN-like protein(NLP)是一类保守的植物特异性转录因子,已在多种植物被证实在调控N响应中发挥关键作用,其中玉米ZmNLP 5是介导氮信号转导和代谢分子网络的中枢基因之一。为了明确ZmNLP 5是否能与ZmSTP 1和ZmAAP 2基因启动子区域的NRE结合,以玉米B73为实验材料,首次利用酵母单杂交技术检测ZmNLP 5与ZmSTP 1、ZmAAP 2基因启动子区域的相互作用。结果表明,将pGADT7-ZmNLP5-1/2分别转化Y1H(pAbAi-ZmSTP1)和Y1H(pAbAi-ZmAAP2)菌株后,在SD/-Leu培养基上均有菌落生长,在含AbA抗生素浓度为200 ng·mL^(-1)的SD/-Leu培养基中只有Y1H(pAbAi-ZmAAP2/pGADT7-ZmNLP5-1)菌株能正常生长。结果说明,ZmNLP 5只与ZmAAP 2基因启动子区域相互作用,ZmNLP 5是能与ZmAAP 2基因启动子NRE结合的转录因子。本研究结果不仅有助于进一步了解玉米硝酸盐信号转导的调控途径,也为今后其他植物硝酸盐信号转导的研究提供理论依据。

Nitrogen(N)is the major limitation factor for its grain production,and both genes contain a NRE cis element in the promoter region.N use efficiency of maize may be improved by increasing the availability of carbon(C).Transporters of ZmSTP1 and ZmAPP2 play important roles in the transport and unloading of C-N assimilates in maize.In addition,both ZmSTP 1 and ZmAAP 2 contain NRE cis elements in promoter regions.NIN-like protein(NLP)is a conserved plant-specific transcription factor family and has been shown in several plant species to be a key player in regulating nitrogen response.ZmNLP 5 is a central hub in a molecular network for mediating N signalling and metabolism.To understand whether ZmNLP 5 is involved in regulating of ZmSTP 1 and ZmAAP 2,we used maize B73 as experimental material to explore the interaction between ZmNLP5,ZmSTP 1 and ZmAAP 2 by yeast one-hybrid system.The results showed that the pGADT7-ZmNLP5-1/2 were transformed into the Y1H(pAbAi-ZmSTP1)and Y1H(pAbAi-ZmAAP2)strains,respectively,they all grew normally on control medium(SD/-Leu).On selection medium(SD/-Leu/+200 ng·mL^(-1) AbA),the growth of Y1H(pAbAi-ZmAAP2/pGADT7-ZmNLP5-1)strain had been in normal.This result suggested that ZmNLP 5 can interact with ZmAAP2 gene,ZmNLP5 is a transcription factor that can bind to the NRE element of ZmAAP 2.The results of this study not only contribute to the further understanding of the regulatory mechanism of nitrate signal transduction in maize,but also provide a theoretical basis for the future study of nitrate signal transduction in other plants.