水稻白叶枯病菌酸性还原酮加双氧酶的鉴定分析

Identification and analysis of acireductone dioxygenase from Xanthomonas oryzae pv.oryzae

酸性还原酮加双氧酶(ARD)催化很多原核和真核生物中的甲硫氨酸急救途径(MSP)倒数第二步。本研究鉴定了水稻白叶枯病菌Xanthomonas oryzae pv.oryzae(Xoo)中的酸性还原酮加双氧酶,命名为xard。Xoo菌株PXO99A、MAFF311018和KACC10331中的xard核苷酸序列完全相同。xard基因突变菌株在甲硫基腺苷(MTA)为唯一硫源时不能正常生长。这一结果证明Xard在MSP中起作用。xard突变体和野生型菌株PXO99A接种水稻IR24后病斑长度数据表明该基因突变对Xoo在水稻上的毒性没有影响。

Acireductone dioxygenase （ARD） is an enzyme catalyzing the penultimate step of the methionine salvage pathway （MSP） in ubiquitous prokaryotic and eukaryotic organisms. Here the counterpart gene in Xan- thomonas oryzae pv. oryzae （Xoo）, named xard was identified. The nucleotide sequences of xard shared the entire identities in Xoo strains PXO99A, MAFF311018 and KACC10331. The strain with an inactive form of xard could not grow normally when methylthioadenosine （MTA） as the exclusive sulfur source. This result confirmed that Xard functioned in MSP. Post inoculation of xard mutant and wild type strain PXO99A on rice line IR24, the lesion length data of 15 days showed that mutation of xard gene had no effect on virulence of Xoo in rice plant IR24.