OsAGSW1, an ABC1-like kinase gene, is involved in the regulation of grain size and weight in rice.
Grain shape and weight are two determining agronomic traits of rice yield. ABC1 (Activity of bc1 complex) is a newly found atypical kinase in plants. Here, we report on an ABC1 protein kinase gene, OsAGSW1 (ABC1-like kinase related to Grain size and Weight). Expression of OsAGSW1-GFP in rice revealed that OsAGSW1 is localized to the chloroplasts in rice. Analysis of OsAGSW1 promoter::β-glucuronidase transgenic rice indicated that this gene was highly expressed in vascular bundles in shoot, hull and caryopsis. Furthermore, OsAGSW1-RNAi and overexpressed transgenic rice lines were generated. Stable transgenic lines overexpressing OsAGSW1 exhibited a phenotype with a significant increase in grain size, grain weight, grain filling rate and 1000-grain weight compared with the wild-type and RNAi transgenic plants. Microscopy analysis showed that spikelet hulls just before heading were different in the OsAGSW1-overexpressed plants compared with wild-type and OsAGSW1 RNAi rice. Further cytological analysis showed that the number of external parenchyma cells in rice hulls of OsAGSW1-overexpressed plants increased, leading to wider and longer spikelet hulls than those of the wild-type and OsAGSW1-RNAi plants. The vascular cross-sectional area in lemma, carpopodium and ovules also strikingly increased and area of both xylem and phloem were enlarged in the OsAGSW1-overexpressed plants. Thus, our results demonstrated that OsAGSW1 plays an important role in seed shape and size of rice by regulating the number of external parenchyma cells and the development of vascular bundles, providing a new insight into the functions of ABC1 genes in plants.
Guangdong Key Lab of Biotechnology for Plant Development, College of Life Science, South China Normal University, Guangzhou 510631, China Vegetable Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou, Guangdong, 510640, China.
Tao
T
Li
Guangdong Key Lab of Biotechnology for Plant Development, College of Life Science, South China Normal University, Guangzhou 510631, China.
Jieming
J
Jiang
Guangdong Key Lab of Biotechnology for Plant Development, College of Life Science, South China Normal University, Guangzhou 510631, China.
Shengchun
S
Zhang
Guangdong Key Lab of Biotechnology for Plant Development, College of Life Science, South China Normal University, Guangzhou 510631, China.
Haoran
H
Shu
Guangdong Key Lab of Biotechnology for Plant Development, College of Life Science, South China Normal University, Guangzhou 510631, China.
Yaqin
Y
Wang
Guangdong Key Lab of Biotechnology for Plant Development, College of Life Science, South China Normal University, Guangzhou 510631, China.
Jianbin
J
Lai
Guangdong Key Lab of Biotechnology for Plant Development, College of Life Science, South China Normal University, Guangzhou 510631, China.
Jinju
J
Du
Guangdong Key Lab of Biotechnology for Plant Development, College of Life Science, South China Normal University, Guangzhou 510631, China Yangchw@scnu.edu.cn.
Chengwei
C
Yang
D002523:Edible Grain / Q000235:genetics* / Q000254:growth & development*; D018506:Gene Expression Regulation, Plant; D012275:Oryza / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D034622:RNA Interference
D010940:Plant Proteins
ABC1-like kinase; OsAGSW1.; grain development; grain size; grain weight; grain width