National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.
National Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing, 210095, China.
Plant Cell Rep. 2017 Oct;36(10):1655-1666. doi: 10.1007/s00299-017-2181-5. Epub 2017 Jul 21.
WSL4 encodes a KCS6 protein which is required for cuticular wax accumulation in rice. Very long chain fatty acids (VLCFAs) are essential precursors for cuticular wax biosynthesis. VLCFA biosynthesis occurs in the endoplasmic reticulum and requires the fatty acid elongase (FAE) complex. The β-ketoacyl-coenzyme A synthase (KCS) catalyzes the first step of FAE-mediated VLCFA elongation. Here we characterized the Wax Crystal-Sparse Leaf 4 (WSL4) gene involved in leaf cuticular wax accumulation in rice. The wsl4 mutant displayed a pleiotropic phenotype including dwarfism, less tiller numbers and reduced surface wax load. Map-based cloning and nucleotide sequencing results revealed that wsl4 carried a single nucleotide substitution in the second exon of a putative KCS6 gene, encoding one subunit of the FAE complex for VLCFAs. Genetic complementation confirmed that the mutation in WSL4 was responsible for the phenotype of wsl4. WSL4 was constitutively expressed in various rice tissues and localized in the endoplasmic reticulum. Both WSL4-RNAi transgenic lines and WSL4 knocked-out mutants exhibited wax-deficient phenotypes similar to the wsl4 mutant. These data indicate that WSL4 is required for cuticular wax accumulation in rice.
WSL4 编码一个 KCS6 蛋白，该蛋白对于水稻角质层蜡的积累是必需的。长链脂肪酸（VLCFAs）是角质层蜡生物合成的必需前体。VLCFA 的生物合成发生在内质网中，需要脂肪酸延长酶（FAE）复合物。β-酮酰基辅酶 A 合酶（KCS）催化 FAE 介导的 VLCFA 伸长的第一步。在这里，我们研究了参与水稻叶片角质层蜡积累的 Wax Crystal-Sparse Leaf 4（WSL4）基因。wsl4 突变体表现出多种表型，包括矮化、分蘖数减少和表面蜡载量减少。基于图谱的克隆和核苷酸测序结果表明，wsl4 在一个假定的 KCS6 基因的第二外显子中携带一个单核苷酸取代，该基因编码 VLCFA 的 FAE 复合物的一个亚基。遗传互补证实，WSL4 中的突变是 wsl4 表型的原因。WSL4 在各种水稻组织中持续表达，并定位于内质网中。WSL4-RNAi 转基因系和 WSL4 敲除突变体都表现出类似于 wsl4 突变体的蜡缺陷表型。这些数据表明 WSL4 是水稻角质层蜡积累所必需的。
