Frontiers in Plant Science (Feb 2019)

Rice Morphogenesis and Chlorophyll Accumulation Is Regulated by the Protein Encoded by NRL3 and Its Interaction With NAL9

  • Wei Chen,
  • Wei Chen,
  • Zhonghua Sheng,
  • Yicong Cai,
  • Qianlong Li,
  • Qianlong Li,
  • Xiangjin Wei,
  • Lihong Xie,
  • Guiai Jiao,
  • Gaoneng Shao,
  • Shaoqing Tang,
  • Jianlong Wang,
  • Peisong Hu,
  • Peisong Hu

DOI
https://doi.org/10.3389/fpls.2019.00175
Journal volume & issue
Vol. 10

Abstract

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Rice yield is closely related to plant leaf shape and chlorophyll content. In this study, we isolated and identified a narrow and rolled leaf mutant, temporarily named nrl3 with darker green leaves. Histological analysis showed that nrl3 has a reduced number of vascular bundles and undergoes abnormal abaxial sclerenchymatous cell differentiation. The NRL3 mutant phenotype was controlled by a single recessive gene, fine-mapped to a 221 kb interval between Indel3 and RM2322 on Chr3. There are 42 ORF in this interval. Sequencing identified an SNP mutant leading to a premature stop in ORF 18, the candidate gene. Bioinformation analysis indicated that NRL3 encodes a novel protein with unknown function. NRL3 is localized in cytoplasm, membrane and nucleus. Expression analysis of nrl3 showed that genes involved in chlorophyll synthesis were significantly up-regulated while those involved in chlorophyll degradation and programmed cell death (PCD) were significantly down-regulated. The expression levels of photosynthesis genes were also affected. Y2H and BIFC assays indicated that NRL3 interacts directly with NAL9/VYL to regulate leaf morphology in rice. Thus, NRL3 plays an important role in leaf morphogenesis and chlorophyll accumulation, and can be used as a new gene resource for constructing improved rice.

Keywords