Integrated physiologic, genomic and transcriptomic strategies involving the adaptation of allotetraploid rapeseed to nitrogen limitation

BMC Plant Biology

Chun-yun Guan¹  Qiong Liao²  Zhen-hua Zhang²  Jun-yue Yao²  Hai-xing Song²  Ting Zhou²  Ying-peng Hua²  Gui-hong Liang² 

[1] National Center of Oilseed Crop Improvement, Hunan Branch;Southern Regional Collaborative Innovation Center for Grain and Oil Crops in China, College of Resources and Environmental Sciences, Hunan Agricultural University;

关键词: Allotetraploid rapeseed;    Genomic selection;    BnamiR827-BnaNLA1s-BnaNRT1.7 s;    Nitrogen limitation adaptation;    Nitrogen use efficiency;    Transcriptional profiling;   

DOI  :  10.1186/s12870-018-1507-y

来源: DOAJ

【 摘 要 】

Abstract Background Nitrogen (N) is a macronutrient that is essential for optimal plant growth and seed yield. Allotetraploid rapeseed (AnAnCnCn, 2n = 4x = 38) has a higher requirement for N fertilizers whereas exhibiting a lower N use efficiency (NUE) than cereal crops. N limitation adaptation (NLA) is pivotal for enhancing crop NUE and reducing N fertilizer use in yield production. Therefore, revealing the genetic and molecular mechanisms underlying NLA is urgent for the genetic improvement of NUE in rapeseed and other crop species with complex genomes. Results In this study, we integrated physiologic, genomic and transcriptomic analyses to comprehensively characterize the adaptive strategies of oilseed rape to N limitation stresses. Under N limitations, we detected accumulated anthocyanin, reduced nitrate (NO3 −) and total N concentrations, and enhanced glutamine synthetase activity in the N-starved rapeseed plants. High-throughput transcriptomics revealed that the pathways associated with N metabolism and carbon fixation were highly over-represented. The expression of the genes that were involved in efficient N uptake, translocation, remobilization and assimilation was significantly altered. Genome-wide identification and molecular characterization of the microR827-NLA1-NRT1.7 regulatory circuit indicated the crucial role of the ubiquitin-mediated post-translational pathway in the regulation of rapeseed NLA. Transcriptional analysis of the module genes revealed their significant functional divergence in response to N limitations between allotetraploid rapeseed and the model Arabidopsis. Association analysis in a rapeseed panel comprising 102 genotypes revealed that BnaC5.NLA1 expression was closely correlated with the rapeseed low-N tolerance. Conclusions We identified the physiologic and genome-wide transcriptional responses of oilseed rape to N limitation stresses, and characterized the global members of the BnamiR827-BnaNLA1s-BnaNRT1.7s regulatory circuit. The transcriptomics-assisted gene co-expression network analysis accelerates the rapid identification of central members within large gene families of plant species with complex genomes. These findings would enhance our comprehensive understanding of the physiologic responses, genomic adaptation and transcriptomic alterations of oilseed rape to N limitations and provide central gene resources for the genetic improvement of crop NLA and NUE.

【 授权许可】

Unknown