Elucidating the machanisms by which control abscisic acid levels in plants

脱落酸（ABA）是一种植物激素，调节多种植物过程，包括种子成熟和避免/适应非生物和生物胁迫。因此，阐明调控内源ABA水平的分子机制是改良种子品质和培育耐胁迫植物的关键。ABA的分泌受9-顺式环氧类胡萝卜素双加氧酶（NCEDs）和ABA 8′-羟化酶（CYP707As）的调控，这两种酶分别是ABA生物合成和分解代谢的限速酶。这些酶定位于特定的细胞类型，并以非细胞自主的方式影响植物的系统反应。因此，从ABA合成细胞到应答细胞的未知ABA运输机制对于这种激素的功能也是必不可少的。本研究计划的重点是识别和功能表征每个植物细胞中这种激素水平的调节，并最终揭示植物如何感知和响应不断变化的环境。

Abscisic acid (ABA) is a plant hormone that regulates a variety of plant processes including seed maturation and avoidance/adaptation to abiotic and biotic stresses. Therefore, elucidation of molecular mechanisms that regulate endogenous ABA level is the key to modify seed qualities and to produce stress tolerant plants. The level of ABA is fine-tuned by the functions of 9-cis-epoxycarotenoid dioxygenases (NCEDs) and ABA 8'-hydroxylases (CYP707As), rate-limiting enzymes of ABA biosynthesis and catabolism, respectively. These enzymes are localized in particular cell types and affect plants' systemic responses in a non-cell autonomous manner. Consequently, unidentified ABA transport machineries from ABA-synthesizing cells to responding cells are also essential for the functions of this hormone. The focus of this research proposal is to identify and functionally characterize the regulation of this hormone levels in each plant cell and ultimately to uncover how plants sense and respond to the changing environment.