Multiple Patterns of Regulation and Overexpression of a Ribonuclease-Like Pathogenesis-Related Protein Gene, OsPR10a, Conferring Disease Resistance in Rice and Arabidopsis.
An abundant 17 kDa RNase, encoded by OsPR10a (also known as PBZ1), was purified from Pi-starved rice suspension-cultured cells. Biochemical analysis showed that the range of optimal temperature for its RNase activity was 40-70°C and the optimum pH was 5.0. Disulfide bond formation and divalent metal ion Mg2+ were required for the RNase activity. The expression of OsPR10a::GUS in transgenic rice was induced upon phosphate (Pi) starvation, wounding, infection by the pathogen Xanthomonas oryzae pv. oryzae (Xoo), leaf senescence, anther, style, the style-ovary junction, germinating embryo and shoot. We also provide first evidence in whole-plant system, demonstrated that OsPR10a-overexpressing in rice and Arabidopsis conferred significant level of enhanced resistance to infection by the pathogen Xoo and Xanthomona campestris pv. campestris (Xcc), respectively. Transgenic rice and Arabidopsis overexpressing OsPR10a significantly increased the length of primary root under phosphate deficiency (-Pi) condition. These results showed that OsPR10a might play multiple roles in phosphate recycling in phosphate-starved cells and senescing leaves, and could improve resistance to pathogen infection and/or against chewing insect pests. It is possible that Pi acquisition or homeostasis is associated with plant disease resistance. Our findings suggest that gene regulation of OsPR10a could act as a good model system to unravel the mechanisms behind the correlation between Pi starvation and plant-pathogen interactions, and also provides a potential application in crops disease resistance.
Graduate School of Biotechnology and Bioengineering, Yuan Ze University, Jhongli, Taiwan.
Li-Fen
LF
Huang
Department of Horticulture and Biotechnology, Chinese Culture University, Taipei, Taiwan.
Kuan-Hung
KH
Lin
Institute of Plant Biology, National Taiwan University, Taipei, Taiwan.
Siou-Luan
SL
He
Department of Life Science, National Taiwan Normal University, Taipei, Taiwan.
Jyh-Lang
JL
Chen
Department of Agronomy, National Chiayi University, Chiayi, Taiwan.
Jian-Zhi
JZ
Jiang
Department of Agronomy, National Chiayi University, Chiayi, Taiwan.
Bo-Hong
BH
Chen
Department of Plant Medicine, National Chiayi University, Chiayi, Taiwan.
Yi-Syuan
YS
Hou
Department of Biochemical Science and Technology, National Chiayi University, Chiayi, Taiwan.
Ruey-Shyang
RS
Chen
Department of Agricultural Chemistry, National Taiwan University, Taipei, Taiwan.
Chwan-Yang
CY
Hong
Department of Agronomy, National Chiayi University, Chiayi, Taiwan.
Shin-Lon
SL
Ho
D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism*; D060467:Disease Resistance / Q000235:genetics / Q000502:physiology; D018506:Gene Expression Regulation, Plant / Q000235:genetics / Q000502:physiology; D012275:Oryza / Q000235:genetics / Q000378:metabolism*; D010710:Phosphates / Q000378:metabolism; D010935:Plant Diseases / Q000382:microbiology; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified / Q000235:genetics / Q000378:metabolism*; D012260:Ribonucleases / Q000235:genetics / Q000378:metabolism*; D014974:Xanthomonas / Q000472:pathogenicity*
D010710:Phosphates; D010940:Plant Proteins; D012260:Ribonucleases