生物谷報道：日本名古屋大學(xué)科學(xué)家日前發(fā)現(xiàn)一種名為“ＳＩＰＫ”的蛋白激酶，它可控制植物的免疫反應(yīng),。
據(jù)日本媒體１日報道,，名古屋大學(xué)科學(xué)家吉岡博文等人在最新一期美國植物生理學(xué)會的《植物細(xì)胞》雜志上撰文指出,，病原菌一旦侵入植物細(xì)胞內(nèi),，植物會生成活性氧和活性氮。以此為信號，植物體內(nèi)發(fā)生各種免疫反應(yīng)以抗擊病原菌,。歐美科學(xué)家發(fā)現(xiàn),，控制植物免疫反應(yīng)過程的應(yīng)該是與這一過程有關(guān)聯(lián)的特殊酶集合體，但是具體控制這一過程的酶一直未被確定,。為了找到這種酶,，吉岡博文等人對這種特殊酶集合體進(jìn)行了仔細(xì)研究。
科學(xué)家首先將病原菌注入植物細(xì)胞內(nèi),，再利用基因技術(shù)逐個抑制特殊酶集合體中的每種酶,。結(jié)果顯示，當(dāng)抑制蛋白激酶“ＳＩＰＫ”時,，植物活性氧和活性氮生成速度大大放慢,，從而導(dǎo)致植物體內(nèi)免疫反應(yīng)非常不明顯?？茖W(xué)家因此認(rèn)定,，“ＳＩＰＫ”是控制植物免疫反應(yīng)的酶。
吉岡博文等人在這一發(fā)現(xiàn)的基礎(chǔ)上研制出一種體內(nèi)“ＳＩＰＫ”非?；钴S的馬鈴薯,，而活躍的“ＳＩＰＫ”使馬鈴薯抗病能力大大增強(qiáng)?？茖W(xué)家計劃今后利用這一成果研制出更多抗病能力很強(qiáng)的蔬菜,。（新華網(wǎng)）
生物谷推薦原始出處：
Plant Cell Advance Online Publication
Published on May 30, 2008; 10.1105/tpc.107.055855
Received September 25, 2007
Returned for revision April 13, 2008
Accepted May 7, 2008
MAPK Signaling Regulates Nitric Oxide and NADPH Oxidase-Dependent Oxidative Bursts in Nicotiana benthamiana
Shuta Asai 1, Kohji Ohta 2, and Hirofumi Yoshioka 1*
1 Laboratory of Defense in Plant–Pathogen Interactions, Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa, Nagoya 464-8601, Japan
2 Plant Pathology Laboratory, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya 464-8601, Japan
* To whom correspondence should be addressed. E-mail: [email protected] .
Nitric oxide (NO) and reactive oxygen species (ROS) act as signals in innate immunity in plants. The radical burst is induced by INF1 elicitin, produced by the oomycete pathogen Phytophthora infestans. NO ASSOCIATED1 (NOA1) and NADPH oxidase participate in the radical burst. Here, we show that mitogen-activated protein kinase (MAPK) cascades MEK2-SIPK/NTF4 and MEK1-NTF6 participate in the regulation of the radical burst. NO generation was induced by conditional activation of SIPK/NTF4, but not by NTF6, in Nicotiana benthamiana leaves. INF1- and SIPK/NTF4-mediated NO bursts were compromised by the knockdown of NOA1. However, ROS generation was induced by either SIPK/NTF4 or NTF6. INF1- and MAPK-mediated ROS generation was eliminated by silencing Respiratory Burst Oxidase Homolog B (RBOHB), an inducible form of the NADPH oxidase. INF1-induced expression of RBOHB was compromised in SIPK/NTF4/NTF6-silenced leaves. These results indicated that INF1 regulates NOA1-mediated NO and RBOHB-dependent ROS generation through MAPK cascades. NOA1 silencing induced high susceptibility to Colletotrichum orbiculare but not to P. infestans; conversely, RBOHB silencing decreased resistance to P. infestans but not to C. orbiculare. These results indicate that the effects of the radical burst on the defense response appear to be diverse in plant–pathogen interactions.
