Ma Yingxuan, Stafford Luke, Ratcliffe Julian, Bacic Antony, Johnson Kim L
School of BioSciences, University of Melbourne, Parkville, VIC 3052, Australia.
La Trobe Institute for Agriculture & Food, Department of Animal, Plant and Soil Science, AgriBio Building, La Trobe University, Bundoora, VIC 3086, Australia.
Plants (Basel). 2022 Sep 2;11(17):2297. doi: 10.3390/plants11172297.
Wall-associated kinases/kinase-likes (WAKs/WAKLs) are plant cell surface sensors. A variety of studies have revealed the important functions of WAKs/WAKLs in regulating cell expansion and defense in cells with primary cell walls. Less is known about their roles during the development of the secondary cell walls (SCWs) that are present in xylem vessel (XV) and interfascicular fiber (IF) cells. In this study, we used RNA-seq data to screen WAKs/WAKLs members that may be involved in SCW development and identified as a candidate. We obtained T-DNA insertion mutants (inserted at the promoter region) and (inserted at the first exon) and compared the phenotypes to wild-type (WT) plants. Decreased transcript levels in stems were found in the mutant plants, and the phenotypes observed included reduced stem length and thinner walls in XV and IFs compared with those in the WT plants. Cell wall analysis showed no significant changes in the crystalline cellulose or lignin content in mutant stems compared with those in the WT. We found that had alternative spliced versions predicted to have only extracellular regions, which may interfere with the function of the full-length version of . Our results suggest WAKL8 can regulate SCW thickening in Arabidopsis stems.
细胞壁相关激酶/类激酶（WAKs/WAKLs）是植物细胞表面传感器。各种研究已经揭示了WAKs/WAKLs在调节具有初生细胞壁的细胞的细胞扩张和防御中的重要功能。关于它们在木质部导管（XV）和束间纤维（IF）细胞中存在的次生细胞壁（SCWs）发育过程中的作用，人们了解较少。在本研究中，我们使用RNA测序数据筛选可能参与SCW发育的WAKs/WAKLs成员，并鉴定出 作为候选者。我们获得了T-DNA插入突变体 （插入启动子区域）和 （插入第一个外显子），并将其表型与野生型（WT）植物进行比较。在 突变体植物中发现茎中的 转录水平降低，观察到的表型包括与WT植物相比，XV和IFs中的茎长度缩短和细胞壁变薄。细胞壁分析表明，与WT相比，突变体茎中的结晶纤维素或木质素含量没有显著变化。我们发现 具有预测仅具有细胞外区域的可变剪接版本，这可能会干扰全长版本 的功能。我们的结果表明WAKL8可以调节拟南芥茎中的SCW增厚。
