Chinese Bulletin of Botany ›› 2021, Vol. 56 ›› Issue (1): 1-5.DOI: 10.11983/CBB20208

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Genomic Basis of Rice Adaptation to Soil Nitrogen Status

Wei Xuan, Guohua Xu*()   

  1. State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China
  • Received:2020-12-25 Accepted:2020-12-29 Online:2021-01-01 Published:2021-01-15
  • Contact: Guohua Xu

Abstract: Crop productivity relies heavily on inorganic nitrogen (N) fertilization, while excess application of N fertilizers results in detrimental effects on ecosystem and plant developmental process. Thus, the improvement of crop N use efficiency (NUE) is critical for the development of sustainable agriculture. Thus far, significant advances in understanding the regulation of NUE have been achieved in rice (Oryza sativa), one of the most important food crops. Several key transporter and regulatory genes involved in N uptake, translocation, and metabolism have been cloned and characterized in rice. However, the genetic mechanisms underlying the geographic adaptation of rice to the change of local soil N status remain elusive. Recently, a team led by Prof. Chengcai Chu, in Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, evaluated the responses to N supplies of rice germplasm resources collected from different eco-geographical regions worldwide. By performing genome-wide association study on rice tillering response to N (TRN), OsTCP19 is identified as a repressor of TRN, and a 29 bp InDel polymorphism in its promoter determines TRN variations among the rice varieties. OsTCP19 regulates TRN by inhibiting the transcription of DLT, a tiller-promoting gene, whilst the transcription of OsTCP19 itself is controlled by a N responsive suppressor LATERAL ORGAN BOUNDARIES DOMAIN (LBD) protein. Notably, OsTCP19 haplotypes were selected among rice germplasms and correlated with local soil N content. This study not only reveals the genetic basis of geographic adaptation of cultivated rice to the changes of soil N environment, but also provides novel genetic candidates for effective breeding of higher NUE rice cultivars.

Key words: rice (Oryza sativa), tillering response to nitrogen, genome-wide association study, nitrogen use efficiency, geographic adaptation, OsTCP19, OsLBD, DLT