A cotton cDNA (GaPR-10) encoding a pathogenesis-related 10 protein with in vitro ribonuclease activity

作者：Zhou, XJ; Lu, S; Xu, YH; Wang, JW; Chen, XY^*

来源：Plant Science, 2002, 162(4): 629-636.

DOI：10.1016/S0168-9452(02)00002-X

• Gossypium arboreum
• GaPR-10
• site-directed mutagenesis
• ribonuclease
• Verticillium dahliae elicitation

A cDNA, GaPR-10, encoding a pathogenesis-related class 10 protein, was isolated from Gossypitum arboreum, a diploid cotton species. The predicted protein of 159 amino acids contains a conserved domain (K-A-X-E-X-Y-L) in the C-terminal helix. The glycine-rich P-loop structure found in Betvl [1] is variable in GaPR-10. The bacterially expressed GaPR-10 exhibited ribonuclease activity in vitro. Substitution of Glu(148) with Lys, and Tyr(150) with Phe, respectively, remarkably decreased the activity, suggesting that both residues in the C-terminus play a major role in catalyzing RNA degradation. Substitution of Gly(51) with Ala, Lys(55) with Asn (both in the P-loop region), and Glu(96) with Lys, affected the activity by 50-60%, indicating that these amino acid residues might be related, but not essential to RNase activity. RNA blot analysis detected a certain level of GaPR-10 transcripts in roots of untreated seedlings, and the transcript level was elevated after the seedlings were treated with Verticillium dahliae elicitors. In G. arboreum suspension cells, induction of GaPR-10 transcription by the fungal elicitor was gradual and prolonged, and the transcription was also inducible by jasmonate, but not by salicylic acid and 1-aminocyclopropane-1-carboxylate.

• 出版日期2002-4
• 单位中国科学院; 植物分子遗传国家重点实验室; 中国科学院上海生命科学研究院