Overexpression of phytosulfokine-α induces male sterility and cell growth by regulating cell wall development in Arabidopsis.
Over-production of functional PSK-α in Arabidopsis caused increases in both plant cell growth and biomass and induced male sterility by regulating cell wall development. Phytosulfokine-α (PSK-α) is a novel disulfated pentapeptide hormone that is involved in promoting plant cell growth. Although a role for PSK-α in stimulating protoplast expansion has been suggested, how PSK-α regulates cell growth in planta remains poorly understood. In this study, we found that overexpression of the normal PSK-α precursor gene AtPSK4, which resulted in high levels of PSK-α, caused longer roots and larger leaves with enlarged cells. As expected, these changes were not observed in transgenic plants overexpressing mutated AtPSK4, which generated unsulfated PSK-α. These findings confirmed the role of PSK-α in promoting plant cell growth. Furthermore, we found that overexpressing AtPSK4, but not mutated AtPSK4, induced a phenotype of male sterility that resulted from the failure of fibrous cell wall development in the endothecium. In addition, overexpressing AtPSK4 enhanced expression of a number of genes encoding expansins, which are involved in cell wall loosening. Accordingly, in addition to its role in cell growth, we propose a novel function for PSK-α signaling in the modulation of plant male sterility via regulation of cell wall development.
Shanghai Key Lab of Bio-energy Crops, School of Life Sciences, Shanghai University, Shanghai, 200444, China.
Liangliang
L
Yu
Shanghai Key Lab of Bio-energy Crops, School of Life Sciences, Shanghai University, Shanghai, 200444, China.
Yan
Y
Liu
Shanghai Key Lab of Bio-energy Crops, School of Life Sciences, Shanghai University, Shanghai, 200444, China.
Yumin
Y
Liu
Shanghai Key Lab of Bio-energy Crops, School of Life Sciences, Shanghai University, Shanghai, 200444, China.
Qiong
Q
Li
Shanghai Key Lab of Bio-energy Crops, School of Life Sciences, Shanghai University, Shanghai, 200444, China.
Guirong
G
Tang
Shanghai Key Lab of Bio-energy Crops, School of Life Sciences, Shanghai University, Shanghai, 200444, China. liluo@shu.edu.cn.
Li
L
Luo
D017360:Arabidopsis / Q000166:cytology* / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D049109:Cell Proliferation; D002473:Cell Wall / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D036361:Peptide Hormones / Q000235:genetics / Q000378:metabolism*; D051479:Plant Infertility; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D018517:Plant Roots / Q000235:genetics; D030821:Plants, Genetically Modified; D011058:Pollen / Q000378:metabolism; D011498:Protein Precursors / Q000235:genetics / Q000378:metabolism*; D015854:Up-Regulation / Q000235:genetics
D029681:Arabidopsis Proteins; C100975:PSK-alpha protein, plant; C000616512:PSK4 protein, Arabidopsis; D036361:Peptide Hormones; D010940:Plant Proteins; D011498:Protein Precursors
Arabidopsis; Cell growth; Male sterility; PSK-α; Peptide hormone