Gene-for-gene defense of wheat against the hessian fly lacks a classical oxidative burst
Gene-for-gene defense of wheat against the hessian fly lacks a classical oxidative burst
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DOI：
10.1094/mpmi-19-1023
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发表时间：
2006-09-01
影响因子：
3.5
通讯作者：
Williams, Christie E.
中科院分区：
文献类型：
--
作者：
Giovanini, Marcelo P.;Puthoff, David P.;Williams, Christie E.
植物与微生物病原体的相互作用和小麦与黑森蝇幼虫的相互作用之间的遗传相似性促使我们研究防御和反防御机制。植物氧化猝发，即在与病原体相互作用的最初24小时内活性氧（AOS）水平的快速增加，通常与由基因对基因识别事件触发的防御相关，类似于涉及小麦和黑森蝇幼虫的防御。黑森蝇超氧化物歧化酶（SOD）和过氧化氢酶（CAT）基因编码的RNA，参与AOS的解毒，增加在一龄幼虫在兼容和不兼容的相互作用。然而，产生超氧化物（O-2（-））的小麦NADPH氧化酶（NOX）基因的mRNA水平没有增加。此外，用二苯撑碘抑制小麦NOX酶并不导致无毒幼虫存活率的增加。然而，硝基蓝四唑染色表明，O-2（-）的基础水平存在于未受感染和受感染的小麦组织。mRNA编码的小麦基因参与解毒的细胞环境，SOD，CAT和谷胱甘肽-S-转移酶没有增加的丰度。组织化学染色与3，3-二氨基联苯胺显示没有增加小麦过氧化氢（H2O2）在侵染过程中，与幼虫SOD和CAT mRNA的变化。然而，用2 '，7'-二氯荧光素处理证明了在受侵染和未受侵染植物的伸长区中存在基础水平的H2O2。小麦黄烷酮3-羟化酶mRNA的积累与幼虫基因mRNA的表达谱有一定的相似性。这些结果表明，幼虫遇到的压力施加的机制以外的氧化爆发在小麦幼苗。
Genetic similarities between plant interactions with microbial pathogens and wheat interactions with Hessian fly larvae prompted us to investigate defense and counterdefense mechanisms. Plant oxidative burst, a rapid increase in the levels of active oxygen species (AOS) within the initial 24 h of an interaction with pathogens, commonly is associated with defenses that are triggered by gene-for-gene recognition events similar to those involving wheat and Hessian fly larvae. RNAs encoded by Hessian fly superoxide dismutase (SOD) and catalase (CAT) genes, involved in detoxification of AOS, increased in first-instar larvae during both compatible and incompatible interactions. However, mRNA levels of a wheat NADPH oxidase (NOX) gene that generates superoxide (O-2(-)) did not increase. In addition, inhibiting wheat NOX enzyme with diphenyleneiodonimn did not result in increased survival of avirulent larvae. However, nitro blue tetrazolium staining indicated that basal levels of O-2(-) are present in both uninfested and infested wheat tissue. mRNA encoded by wheat genes involved in detoxification of the cellular environment, SOD, CAT, and glutathione-S-transferase did not increase in abundance. Histochemical staining with 3,3-diaminobenzidine revealed no increases in wheat hydrogen peroxide (H2O2) during infestation that were correlated with the changes in larval SOD and CAT mRNA. However, treatment with 2',7'-dichlorofluorescin demonstrated the presence of basal levels of H2O2 in the elongation zone of both infested and uninfested plants. The accumulation of a wheat flavanone 3-hydroxylase mRNA did show some parallels with larval gene mRNA profiles. These results suggested that larvae encounter stresses imposed by mechanisms other than an oxidative burst in wheat seedlings.