GDSL lipase occluded stomatal pore 1 is required for wax biosynthesis and stomatal cuticular ledge formation. Issue 6 (24th July 2020)

• Record Type: Journal Article
• Authors: Tang, Jing; Yang, Xianpeng; Xiao, Chuanlei; Li, Jiaying; Chen, Yongqiang; Li, Ruiying; Li, Shipeng; Lü, Shiyou; Hu, Honghong
• Is Part Of: New phytologist. Volume 228:Issue 6(2020)
• Page Start: 1880
• Page End: 1896
• Publication Date: 2020-07-24
• Subjects: Arabidopsis -- drought tolerance -- epidermal permeability -- OSP1 -- stomatal outer cuticular ledge -- thioesterase activity -- water loss -- wax biosynthesis; Botany -- Periodicals; 580
• DOI: 10.1111/nph.16741
• Languages: English
• ISSNs: 0028-646X

Abstract

Summary: 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. OSP1 mutation 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 vitro enzymatic assays demonstrated that OSP1 possesses thioesterase activity, particularly on C22:0 and C26:0 acyl‐CoAs. Genetic interaction analyses with CER1 ( ECERIFERUM 1 ), CER3 ( ECERIFERUM 3 ) and MAH1 ( 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. Abstract : See also the Commentary on this article by Hunt & Gray 228 : 1698–1700 .