title: A novel GRAS transcription factor,ZmGRAS20, regulates starch biosynthesis in rice endosperm.
abstract: Starch occupies the maximal component of cereal grains and is pivotal for maize yield and quality. However, the regulatory mechanism of starch synthesis is still poorly understand. In this study, a GRAS transcription factor,ZmGRAS20, was isolated from maize inbred line B73 based on transcriptome sequencing. Quantitative real-time PCR indicated thatZmGRAS20is specifically expressed in maize endosperm. Transient expression of ZmGRAS20-green fluorescent protein fusion protein in tobacco cells showed a nucleus and membrane localization of the protein. Transactivation assay of ZmGRAS20 demonstrated that it has no transactivation activity in yeast cells. Overexpression ofZmGRAS20led to a chalky region of ventral endosperm with decreased starch content and defective agronomic characters in transgenic seeds. Moreover,ZmGRAS20-overexpression plants had fewer fractions of long-branched starch chains. Further scanning electron microscopy observation ofZmGRAS20transgenic seeds exhibited altered starch granules morphology compared with wide type plants. Taken together, these results suggested thatZmGRAS20may function as a starch synthesis regulatory factor in rice endosperm.
authors.affiliation: National Engineering Laboratory of Crop Stress Resistance/Key Laboratory of Crop Biology of Anhui Province, School of Life Sciences, Anhui Agricultural University, Hefei, 230036 China.
authors.forename: Huilin
authors.initials: H
authors.lastname: Cai
authors.affiliation: National Engineering Laboratory of Crop Stress Resistance/Key Laboratory of Crop Biology of Anhui Province, School of Life Sciences, Anhui Agricultural University, Hefei, 230036 China.
authors.forename: Yulong
authors.initials: Y
authors.lastname: Chen
authors.affiliation: National Engineering Laboratory of Crop Stress Resistance/Key Laboratory of Crop Biology of Anhui Province, School of Life Sciences, Anhui Agricultural University, Hefei, 230036 China.
authors.forename: Min
authors.initials: M
authors.lastname: Zhang
authors.affiliation: National Engineering Laboratory of Crop Stress Resistance/Key Laboratory of Crop Biology of Anhui Province, School of Life Sciences, Anhui Agricultural University, Hefei, 230036 China.
authors.forename: Ronghao
authors.initials: R
authors.lastname: Cai
authors.affiliation: National Engineering Laboratory of Crop Stress Resistance/Key Laboratory of Crop Biology of Anhui Province, School of Life Sciences, Anhui Agricultural University, Hefei, 230036 China.
authors.forename: Beijiu
authors.initials: B
authors.lastname: Cheng
authors.affiliation: National Engineering Laboratory of Crop Stress Resistance/Key Laboratory of Crop Biology of Anhui Province, School of Life Sciences, Anhui Agricultural University, Hefei, 230036 China.
authors.forename: Qing
authors.initials: Q
authors.lastname: Ma
authors.affiliation: National Engineering Laboratory of Crop Stress Resistance/Key Laboratory of Crop Biology of Anhui Province, School of Life Sciences, Anhui Agricultural University, Hefei, 230036 China.
authors.forename: Yang
authors.identifier: 0000-0001-7886-4843
authors.initials: Y
authors.lastname: Zhao
keywords: Endosperm; Maize; Quality; Starch synthesis; ZmGRAS20