據(jù)此間報(bào)道，在3月31日的PNAS（《美國(guó)科學(xué)院院刊》）網(wǎng)絡(luò)版上公布了由中國(guó)農(nóng)業(yè)大學(xué)植物生理和生物化學(xué)國(guó)家重點(diǎn)實(shí)驗(yàn)室,、美國(guó)密蘇里州大學(xué)和明尼蘇達(dá)州大學(xué)的研究人員合作進(jìn)行的一項(xiàng)新研究,。研究發(fā)現(xiàn)一種真菌應(yīng)答MAPK（一種激酶）級(jí)聯(lián)調(diào)節(jié)著模式植物擬南芥中的植物抗毒素生物合成過程,。這篇文章的通訊作者是美國(guó)密蘇里大學(xué)的華人學(xué)者Shuqun Zhang，第一作者是我校生物學(xué)院任東濤教授,。
MAPK3和MAPK6是兩種擬南芥分裂活化蛋白激酶（MAPK）,。植物對(duì)病原的識(shí)別能致MAPK3和MAPK6迅速激活。研究人員在這篇新文章中報(bào)告：擬南芥中一種重要的植物抗毒素——camalexin受到MAPK3/MAPK6級(jí)聯(lián)的調(diào)節(jié)?；顫姷纳嫌蜯APK激酶（MAPKK）或MAPKK激酶（MAPKKK）的表達(dá)引發(fā)的MAPK3/MAPK6激活足以誘導(dǎo)在沒有病原攻擊時(shí)誘導(dǎo)camalexin的合成,。
研究發(fā)現(xiàn)，由灰霉病菌觸發(fā)的植保素camalexin的誘導(dǎo)是MAPK3/MAPK6活化的序幕,，并且會(huì)因MAPK3和MAPK6級(jí)聯(lián)處于PHYTOALXIN DEFICIENT2（PAD2）和PAD3的上游,，但獨(dú)立于PAD1和PAD4，或處于其下游,；MAPK3/MAPK6激活后的camalexin誘導(dǎo)合成則是Trp（色胺酸）生物合成途徑中多基因編碼酶迅速協(xié)同上調(diào)的序幕。
這些研究結(jié)果表明,，MAPK3/MAPK6級(jí)聯(lián)在病因感染后通過對(duì)生物合成基因的轉(zhuǎn)錄調(diào)節(jié)來調(diào)控camalexin的合成,。
生物谷推薦原始出處：
PNAS published March 31, 2008, 10.1073/pnas.0711301105
A fungal-responsive MAPK cascade regulates phytoalexin biosynthesis in Arabidopsis
Dongtao Ren*,, Yidong Liu, Kwang-Yeol Yang,, Ling Han, Guohong Mao, Jane Glazebrook, and Shuqun Zhang,¶
*State Key Laboratory of Plant Physiology and Biochemistry, China Agricultural University, Beijing 100094, China; Department of Biochemistry, University of Missouri, Columbia, MO 65211; and Department of Plant Biology and Center for Microbial and Plant Genomics, University of Minnesota, St. Paul, MN 55108
Edited by Roger N. Beachy, Donald Danforth Plant Science Center, St. Louis, MO, and approved February 14, 2008 (received for review November 29, 2007)
Abstract
Plant recognition of pathogens leads to rapid activation of MPK3 and MPK6, two Arabidopsis mitogen-activated protein kinases (MAPKs), and their orthologs in other species. Here, we report that synthesis of camalexin, the major phytoalexin in Arabidopsis, is regulated by the MPK3/MPK6 cascade. Activation of MPK3/MPK6 by expression of active upstream MAPK kinase (MAPKK) or MAPKK kinase (MAPKKK) was sufficient to induce camalexin synthesis in the absence of pathogen attack. Induction of camalexin by Botrytis cinerea was preceded by MPK3/MPK6 activation, and compromised in mpk3 and mpk6 mutants. Genetic analysis placed the MPK3/MPK6 cascade upstream of PHYTOALEXIN DEFICIENT 2 (PAD2) and PAD3, but independent or downstream of PAD1 and PAD4. Camalexin induction after MPK3/MPK6 activation was preceded by rapid and coordinated up-regulation of multiple genes encoding enzymes in the tryptophan (Trp) biosynthetic pathway, in the conversion of Trp to indole-3-acetaldoxime (IAOx, a branch point between primary and secondary metabolism), and in the camalexin biosynthetic pathway downstream of IAOx. These results indicate that the MPK3/MPK6 cascade regulates camalexin synthesis through transcriptional regulation of the biosynthetic genes after pathogen infection.
