生命是一個艱苦絕倫的過程，尤其是對于植物而言，它們必須忍耐環(huán)境帶來的壓力,，如干旱、冰凍和炎熱,，但它們裝備了一整套的基因,，能夠幫助其面對各種有害環(huán)境條件。植物使用專門的信號,，人們稱之為應激激素，去面對艱難的時期和適應壓力環(huán)境，以增強自身的生存,。其中一種專門的激素——脫落酸（ABA）就是由植物在長期的壓力環(huán)境中,，尤其是干旱環(huán)境中產(chǎn)生的。ABA如何幫助植物忍耐干旱的分子機制尚未得到充分的理解,，而對ABA受體的探索一直備受爭議,，包括多篇科學論文的收回，以及許多重要性受到質(zhì)疑的論文的發(fā)表等,。
一個由美國,、加拿大和西班牙科學家組成的國際科研團隊近日已確認了新的ABA受體。應用一種人工合成的,、科學家通過化學基因組學確認的,、能夠模仿ABA的生長抑制劑pyrabactin，研究者們查明PYR/PYLs是ABA的受體,，其作用位于負性調(diào)節(jié)通路的頂點,。PYR/PYLs通過抑制PP2Cs蛋白的活性來調(diào)控ABA信號通路。而PP2Cs蛋白在ABA信號的傳遞過程中扮演關(guān)鍵角色,。
本結(jié)果發(fā)表在Science雜志上,，論文的第一作者——Sean Cutler，敏銳的意識到先前在ABA研究領(lǐng)域的可疑數(shù)據(jù),，所以他采取了一種與眾不同的步驟,，與其他競爭者分享其數(shù)據(jù)，并在結(jié)果公布前將競爭者變成合作者,。在一篇新聞稿中,，加州大學植物細胞生物學中心的主任、也是論文的作者Natasha Raikhel說：“多篇論文已試圖為其發(fā)現(xiàn)的ABA受體做出辯護,，但他們的研究結(jié)果并未經(jīng)受住時間的考驗……我相信這一次Cutler博士和他的團隊已經(jīng)分離到真正的ABA受體,。”（生物谷Bioon.com）
生物谷推薦原始出處：
Science 22 May 2009:DOI: 10.1126/science.1173041
Abscisic Acid Inhibits Type 2C Protein Phosphatases via the PYR/PYL Family of START Proteins
Sang-Youl Park,1,* Pauline Fung,2,* Noriyuki Nishimura,4, Davin R. Jensen,8, Hiroaki Fujii,1 Yang Zhao,2 Shelley Lumba,2 Julia Santiago,5 Americo Rodrigues,5 Tsz-fung F. Chow,2 Simon E. Alfred,2 Dario Bonetta,6 Ruth Finkelstein,7 Nicholas J. Provart,2,3 Darrell Desveaux,2,3 Pedro L. Rodriguez,5 Peter McCourt,2 Jian-Kang Zhu,1 Julian I. Schroeder,4 Brian F. Volkman,8 Sean R. Cutler1,9,10,11,
Type 2C protein phosphatases (PP2Cs) are vitally involved in abscisic acid (ABA) signaling. Here, we show that a synthetic growth inhibitor called pyrabactin functions as a selective ABA agonist. Pyrabactin acts through PYRABACTIN RESISTANCE 1 (PYR1), the founding member of a family of START proteins called PYR/PYLs, which are necessary for both pyrabactin and ABA signaling in vivo. We show that ABA binds to PYR1, which in turn binds to and inhibits PP2Cs. We conclude that PYR/PYLs are ABA receptors functioning at the apex of a negative regulatory pathway that controls ABA signaling by inhibiting PP2Cs. Our results illustrate the power of the chemical genetic approach for sidestepping genetic redundancy.
1 Department of Botany and Plant Sciences, University of California at Riverside, Riverside, CA 92521, USA.
2 Department of Cell and Systems Biology, University of Toronto, 25 Willcocks Street, Toronto, ON, M5S 3B2, Canada.
3 Centre for the Analysis of Genome Evolution and Function, University of Toronto, 25 Willcocks Street, Toronto, ON, M5S 3B2, Canada.
4 Division of Biological Sciences, Cell and Developmental Biology Section, University of California at San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA.
5 Instituto de Biología Molecular y Celular de Plantas, Universidad Politécnica de Valencia, Avenida de los Naranjos, Edificio CPI, 8E, ES-46022 Valencia, Spain.
6 Faculty of Science, University of Ontario Institute of Technology, 2000 Simcoe Street North, Oshawa, ON, L1H 7K4, Canada.
7 Department of Molecular, Cellular, and Developmental Biology, University of California at Santa Barbara, Santa Barbara, CA 93106, USA.
8 Department of Biochemistry, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA.
9 Center for Plant Cell Biology, University of California at Riverside, Riverside, CA 92521, USA.
10 Institute for Genome Biology, University of California at Riverside, Riverside, CA 92521, USA.
11 Department of Chemistry, University of California at Riverside, Riverside, CA 92521, USA.
