Short and narrow flag leaf1, a GATA zinc finger domain-containing protein, regulates flag leaf size in rice (Oryza sativa)

Peilong He,Guanghua He,Yangyang Li,Xiaowen Wang,Jile Ni,Xiaobo Zhang,Xianchun Sang,Yudong Jiang,Weijiang Tian,Xiaoqiong Zhang,Jia Xie,Ying Sun

doi:10.1186/s12870-018-1452-9

Abstract

BackgroundThe flag leaf of rice (Oryza sativa L.) is an important determinant of plant type characteristics and grain yield. Identification of flag leaf mutants of rice is crucial to elucidate the molecular mechanism of flag-leaf development, and for exploitation of rice germplasm resources.ResultsIn this study, we describe a mutant designated short and narrow flag leaf 1 (snfl1). Histological analysis showed that the length of epidermal cells and number of longitudinal veins were decreased in the flag leaf of the snfl1 mutant. Map-based cloning indicated that a member of the GATA family of transcription factors is a candidate gene for SNFL1. A single-nucleotide transition at the last base in the single intron of snfl1 led to variation in alternative splicing and early termination of translation. Complemented transgenic plants harbouring the candidate SNFL1 gene rescued the snfl1 mutant. Analysis of RT-PCR and the SNFL1 promoter by means of a GUS fusion expression assay showed that abundance of SNFL1 transcripts was higher in the culm, leaf sheath, and root. Expression of the SNFL1-GFP fusion protein in rice protoplasts showed that SNFL1 was localized in nucleus.ConclusionsWe conclude that SNFL1 is an important regulator of leaf development, the identification of which might have important implications for future research on GATA transcription factors.

Highlights

The flag leaf of rice (Oryza sativa L.) is an important determinant of plant type characteristics and grain yield
Phenotypes of the snfl1 mutant To investigate the molecular mechanisms that regulate rice leaf development, we used ethyl methanesulfonate (EMS) mutagenesis to generate a population of M2 seedlings derived from 1 kg of rice seeds from the cultivar ‘Jinhui10’
The flag leaf length of snfl1 was dramatically decreased by about 83.28%, and the flag leaf width decreased by about 67.69% compared with the wild type (WT) (Fig. 1b–e)

Summary

Introduction

The flag leaf of rice (Oryza sativa L.) is an important determinant of plant type characteristics and grain yield. As a model monocotyledonous plant, the elucidation of physiological and biochemical mechanisms in rice are important for research on cereals and monocotyledonous species. Among the rice and other major cereals, the uppermost three leaves, especially the flag leaf, are the main source of the carbohydrates that eventually accumulate in the grains [2,3,4,5]. Leaves of the rice dwarf mutant dwarf and gladius leaf 1 (dgl1) are shorter and the edges of the leaf tips more rounded than those of the wild type (WT). An additional rice mutant with an aberrant leaf length, Oryza sativa ent-kaurene synthase 2 (osks2), produces short and dark green leaves in the seedling stage

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Discussion

Conclusion