GDSL lipase occluded stomatal pore 1 is required for wax biosynthesis and stomatal cuticular ledge formation
GDSL lipase occluded stomatal pore 1 is required for wax biosynthesis and stomatal cuticular ledge formation
复制标题
DOI：
10.1111/nph.16741
复制
发表时间：
2020-07-24
期刊：
影响因子：
9.4
通讯作者：
Hu, Honghong
中科院分区：
文献类型：
--
作者：
Tang, Jing;Yang, Xianpeng;Hu, Honghong
植物叶片表面覆盖有防水角质层。气孔成熟后，面对气孔表面的角质层需要被雕刻形成外角质层架（OCL），以进行有效的气体交换。在这里，我们的特点是拟南芥GDSL脂肪酶，气孔孔闭塞1（OSP1），在蜡生物合成和气孔OCL形成的作用。OSP1突变导致叶片蜡质合成减少，气孔关闭，表皮透性增加，蒸腾速率降低，耐旱性增强。OSP1在蜡质生物合成和气孔功能中起着重要作用，体外酶促试验表明OSP1具有硫酯酶活性，尤其是对C22：0和C26：0酰基辅酶A的活性。通过对蜡合成和气孔壁架形成过程中的CER1（ECERIFERUM 1）、CER3（ECERIFERUM 3）和MAH 1（Middle chain Alkane Hydroxylase 1）的遗传互作分析，发现OSP1在蜡合成和气孔壁架形成过程中可能位于CER3的上游，并暗示蜡成分的变化和保持较低水平的酮在气孔壁架的形成中起一定作用。我们的研究结果提供了深入的分子机制介导的蜡生物合成和突出的联系蜡生物合成和气孔OCL的形成过程。
The plant leaf surface is coated with a waterproof cuticle layer. Cuticle facing the stomatal pore surface needs to be sculpted to form outer cuticular ledge (OCL) after stomatal maturation for efficient gas exchange. Here, we characterized the roles of Arabidopsis GDSL lipase, Occlusion of Stomatal Pore 1 (OSP1), in wax biosynthesis and stomatal OCL formation. OSP1mutation results in significant reduction in leaf wax synthesis and occlusion of stomata, leading to increased epidermal permeability, decreased transpiration rate, and enhanced drought tolerance. We demonstrated that OSP1 activity is critical for its role in wax biosynthesis and stomatal function.In vitroenzymatic assays demonstrated that OSP1 possesses thioesterase activity, particularly on C22:0 and C26:0 acyl-CoAs. Genetic interaction analyses withCER1(ECERIFERUM 1),CER3(ECERIFERUM 3) andMAH1(Mid-chain Alkane Hydroxylase 1) in wax biosynthesis and stomatal OCL formation showed that OSP1 may act upstream of CER3 in wax biosynthesis, and implicate that wax composition percentage changes and keeping ketones in a lower level play roles, at least partially, in forming stomatal ledges. Our findings provided insights into the molecular mechanism mediating wax biosynthesis and highlighted the link between wax biosynthesis and the process of stomatal OCL formation.