生物谷：植物含有各種不同的、結(jié)構(gòu)類似于動物體內(nèi)的類固醇激素的類固醇和固醇,。經(jīng)過艱苦研究，油菜素內(nèi)酯（brassinosteroids）已被普遍接受為一種重要的植物激素,。這個通道的一個關(guān)鍵部分是通過BRI1受體及其共受體BAK1對油菜素內(nèi)酯的識別,。但關(guān)于BAK1具有一個完全出乎意料的不同功能的消息可能會使問題復(fù)雜化。當(dāng)先天免疫受體FLS2被其已知配體flagellin 刺激時,，BAK1被發(fā)現(xiàn)專門與該受體結(jié)合,。在bak1基因發(fā)生突變的擬南芥中，先天免疫響應(yīng)大大削弱,。因此,，BAK1似乎在發(fā)育和先天免疫中有雙重作用，同果蠅中著名的TOLL受體一樣,。
原始出處:
Nature 448, 497-500 (26 July 2007) | doi:10.1038/nature05999; Received 27 April 2007; Accepted 7 June 2007; Published online 11 July 2007
A flagellin-induced complex of the receptor FLS2 and BAK1 initiates plant defence
Delphine Chinchilla1, Cyril Zipfel1,2, Silke Robatzek1,3, Birgit Kemmerling4, Thorsten Nürnberger4, Jonathan D. G. Jones2, Georg Felix1,4 & Thomas Boller1
Zurich-Basel Plant Science Center, Botanical Institute, University of Basel, Hebelstrasse 1, 4056 Basel, Switzerland
The Sainsbury Laboratory, Colney Lane, Norwich, Norfolk NR4 7UH, UK
Max-Planck-Institute for Plant Breeding Research, Carl-von-Linné Weg 10, 50829 Cologne, Germany
Institute of Plant Biochemistry, ZMBP, University of Tuebingen, 72076 Tuebingen, Germany
Correspondence to: Delphine Chinchilla1Thomas Boller1 Correspondence and requests for materials should be addressed to D.C. (Email: [email protected]) or T.B. (Email: [email protected]).
Plants sense potential microbial invaders by using pattern-recognition receptors to recognize pathogen-associated molecular patterns (PAMPs)1. In Arabidopsis thaliana, the leucine-rich repeat receptor kinases flagellin-sensitive 2 (FLS2) (ref. 2) and elongation factor Tu receptor (EFR) (ref. 3) act as pattern-recognition receptors for the bacterial PAMPs flagellin4 and elongation factor Tu (EF-Tu) (ref. 5) and contribute to resistance against bacterial pathogens. Little is known about the molecular mechanisms that link receptor activation to intracellular signal transduction. Here we show that BAK1 (BRI1-associated receptor kinase 1), a leucine-rich repeat receptor-like kinase that has been reported to regulate the brassinosteroid receptor BRI1 (refs 6,7), is involved in signalling by FLS2 and EFR. Plants carrying bak1 mutations show normal flagellin binding but abnormal early and late flagellin-triggered responses, indicating that BAK1 acts as a positive regulator in signalling. The bak1-mutant plants also show a reduction in early, but not late, EF-Tu-triggered responses. The decrease in responses to PAMPs is not due to reduced sensitivity to brassinosteroids. We provide evidence that FLS2 and BAK1 form a complex in vivo, in a specific ligand-dependent manner, within the first minutes of stimulation with flagellin. Thus, BAK1 is not only associated with developmental regulation through the plant hormone receptor BRI1 (refs 6,7), but also has a functional role in PRR-dependent signalling, which initiates innate immunity.
圖：bak1 mutants show reduced sensitivity to flagellin in growth assays.
