茉莉酸作為一種與抗逆性密切相關(guān)的植物激素，主要調(diào)控植物對(duì)昆蟲侵害,、病原菌侵染和機(jī)械傷害的抗性反應(yīng)，同時(shí)也參與調(diào)控根系生長,、配子發(fā)育及成熟衰老等發(fā)育過程,。生長素主要在植物的生長發(fā)育過程中起調(diào)控作用。以前的研究證明,，茉莉酸通過調(diào)控生長素的生物合成和極性運(yùn)輸來調(diào)節(jié)擬南芥?zhèn)雀男纬?。生長素的極性輸出由極性定位于質(zhì)膜上的PIN (PIN formed)蛋白介導(dǎo)完成，在植物生長發(fā)育過程中起重要調(diào)控作用,。目前,，關(guān)于生長素極性運(yùn)輸?shù)难芯渴侵参锷飳W(xué)的熱點(diǎn)研究領(lǐng)域之一。
中國科學(xué)院遺傳與發(fā)育生物學(xué)研究所基因組生物學(xué)研究中心李傳友課題組的研究證明,，茉莉酸調(diào)節(jié)PIN2蛋白的內(nèi)吞和在細(xì)胞質(zhì)膜上的積累,。研究發(fā)現(xiàn)，低濃度茉莉酸可以抑制PIN2蛋白的內(nèi)吞,，而且這種作用是依賴ASA1介導(dǎo)的生長素生物合成和TIR1/AFBs介導(dǎo)的生長素信號(hào)轉(zhuǎn)導(dǎo),。而高濃度茉莉酸可以降低野生型擬南芥中PIN2蛋白在細(xì)胞質(zhì)膜上的積累,，特別是在asa1-1突變體中,，高濃度茉莉酸處理嚴(yán)重地降低PIN2蛋白在細(xì)胞質(zhì)膜上的積累。遺傳學(xué)研究表明,，高濃度茉莉酸對(duì)PIN蛋白的這種作用獨(dú)立于生長素信號(hào)途徑,。此項(xiàng)研究還發(fā)現(xiàn)，茉莉酸通過影響生長素在根尖的側(cè)向分布進(jìn)而調(diào)控植物根的向重性反應(yīng),。以上結(jié)果表明,，茉莉酸通過與生長素互作調(diào)節(jié)植物對(duì)外界信號(hào)或環(huán)境的適應(yīng)性反應(yīng)。
該項(xiàng)研究為進(jìn)一步揭示茉莉酸調(diào)控生長素轉(zhuǎn)運(yùn)蛋白胞內(nèi)運(yùn)輸和降解的分子機(jī)制提供了新的思路,。這項(xiàng)成果4月9日在線發(fā)表于國際雜志New Phytologist,。李傳友實(shí)驗(yàn)室孫加強(qiáng)副研究員和在讀博士陳謙為該論文共同第一作者。
該研究得到了科技部和國家自然科學(xué)基金委的資助,。（生物谷Bioon.com）
生物谷推薦原文出處：
New Phytologist DOI: 10.1111/j.1469-8137.2011.03713.x
Jasmonate modulates endocytosis and plasma membrane accumulation of the Arabidopsis PIN2 protein
Jiaqiang Sun1,2,?, Qian Chen1,?, Linlin Qi1, Hongling Jiang1, Shuyu Li1, Yingxiu Xu1, Fang Liu1, Wenkun Zhou1, Jianwei Pan3, Xugang Li2,4, Klaus Palme2,4, Chuanyou Li1,
Keywords:Arabidopsis thaliana;auxin;endocytosis;jasmonate;PIN2
Summary
The subcellular distribution of the PIN-FORMED (PIN) family of auxin transporters plays a critical role in auxin gradient-mediated developmental processes, including lateral root formation and gravitropic growth.?Here, we report two distinct aspects of CORONATINE INSENSITIVE 1 (COI1)- and AUXIN RESISTANT 1 (AXR1)-dependent methyl jasmonate (MeJA) effects on PIN2 subcellular distribution: at lower concentration (5 μM), MeJA inhibits PIN2 endocytosis, whereas, at higher concentration (50 μM), MeJA reduces PIN2 accumulation in the plasma membrane.?We show that mutations of ASA1 (ANTHRANILATE SYNTHASE a1) and the TIR1/AFBs (TRANSPORT INHIBITOR RESPONSE 1/AUXIN-SIGNALING F-BOX PROTEINs) auxin receptor genes impair the inhibitory effect of 5 μM MeJA on PIN2 endocytosis, suggesting that a lower concentration of jasmonate inhibits PIN2 endocytosis through interaction with the auxin pathway. In contrast, mutations of ASA1 and the TIR1/AFBs auxin receptor genes enhance, rather than impair, the reduction effect of 50 μM MeJA on the plasma membrane accumulation of PIN2, suggesting that this action of jasmonate is independent of the auxin pathway. In addition to the MeJA effects on PIN2 endocytosis and plasma membrane residence, we also show that MeJA alters lateral auxin redistribution on gravi-stimulation, and therefore impairs the root gravitropic response.?Our results highlight the importance of jasmonate–auxin interaction in the coordination of plant growth and the adaptation response
