KAR受體KAI2調控擬南芥抗旱

本論文與2017年11月13日發表於PLOS GENETICS，原文題目如下：The karrikin receptor KAI2 promotes drought resistance in Arabidopsis thaliana

乾旱導致作物產量大大降低，我們致力於尋找調控擬南芥抗旱性的化學和遺傳因素。Karrikins(KAR)是煙中發現一種可以促進種子萌發的丁烯酸內脂化合物，已報到其在逆境下可以提高種子活力。本文研究發現KARRIKIN INSENSITIVE2(KAI2) 編碼了一種KAR受體，其突變體對缺水高度敏感。本文從轉錄組學，生理學，生物化學等方面具體分析其抗旱性。kai2突變體水分流失加快，乾旱誘導的細胞膜受損加重，氣孔開度增大，表皮滲透性提高。此外，乾旱導致kai2花青素合成減少，氣孔開度以及子葉張開對ABA高度敏感。通過轉錄組分析鑒定出一些與觀察到的生理和生化變化相關的基因。數據表明ABA信號途徑和KAI2-依賴的信號途徑在調控植物抗旱方面存在相關性。此外，本文為KAI2與D14信號在調控植物抗旱方面提供新思路。

Abstract：

Drought causes substantial reductions in crop yields worldwide. Therefore, we set out to identify new chemical and genetic factors that regulate drought resistance in Arabidopsis thaliana. Karrikins (KARs) are a class of butenolide compounds found in smoke that promote seed germination, and have been reported to improve seedling vigor under stressful growth conditions. Here, we discovered that mutations in KARRIKIN INSENSITIVE2 (KAI2), encoding the proposed karrikin receptor, result in hypersensitivity to water deprivation. We performed transcriptomic, physiological and biochemical analyses of kai2 plants to understand the basis for KAI2-regulated drought resistance. We found that kai2 mutants have increased rates of water loss and drought-induced cell membrane damage, enlarged stomatal apertures, and higher cuticular permeability. In addition, kai2 plants have reduced anthocyanin biosynthesis during drought, and are hyposensitive to abscisic acid (ABA) in stomatal closure and cotyledon opening assays. We identified genes that are likely associated with the observed physiological and biochemical changes through a genome-wide transcriptome analysis of kai2 under both well-watered and dehydration conditions. These data provide evidence for crosstalk between ABA- and KAI2-dependent signaling pathways in regulating plant responses to drought. A comparison of the strigolactone-insensitive mutant d14 (DWARF14) to kai2 indicated that strigolactones also contributes to plant drought adaptation, although not by affecting cuticle development. Our findings suggest that chemical or genetic manipulation of KAI2 and D14 signaling may provide novel ways to improve drought resistance.

每日一詞：

hyposensitive

英[?ha?p?sens?t?v]

美[?ha?p?sens?t?v]

adj. 弱敏的，敏感度減弱的;

[例句]Determination of magnesium in rare earth-magnesium intermediate alloy by atomic absorption spectrometry with hyposensitive line

次靈敏線火焰原子吸收光譜法測定稀土-鎂中間合金中鎂

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