Liu Xiaomeng, He Xiao, Liu Zhongbing, Wu Peiyin, Tang Ning, Chen Zexiong, Zhang Weiwei, Rao Shen, Cheng Shuiyuan, Luo Chengrong, Xu Feng
College of Horticulture and Gardening, Yangtze University, Jingzhou 434025, Hubei, China.
School of Horticulture and Landscape, Wuhan University of Bioengineering, Wuhan, China.
Genomics. 2022 May;114(3):110374. doi: 10.1016/j.ygeno.2022.110374. Epub 2022 Apr 27.
Zanthoxylum armatum DC. is an important economic tree species. Prickle is a type of trichome with special morphology, and there are a lot of prickles on the leaves of Z. armatum, which seriously restricts the development of Z. armatum industry. In this study, the leaves of Z. armatum cv. Zhuye (ZY) and its budding variety 'Rongchangwuci' (WC) (A less prickly mutant variety) at different developmental stages were used as materials, and the transcriptome sequencing data were analyzed. A total of 96,931 differentially expressed genes (DEGs) were identified among the samples, among which 1560 were candidate DEGs that might be involved in hormone metabolism. The contents of JA, auxin and CK phytohormones in ZY leaves were significantly higher than those in WC leaves. Combined with weighted gene co-expression network analysis, eight genes (MYC, IAA, ARF, CRE/AHK, PP2C, ARR-A, AOS and LOX) were identified, including 25 transcripts, which might affect the metabolism of the three hormones and indirectly participate in the formation of prickles. Combining with the proteins successfully reported in other plants to regulate trichome formation, ZaMYB86, a transcription factor of R2R3 MYB family, was identified through local Blast and phylogenetic tree analysis, which might regulate prickle formation of Z. armatum. Overexpression of ZaMYB86 in mutant A. thaliana resulted in the reduction of trichomes in A. thaliana leaves, which further verified that ZaMYB86 was involved in the formation of pickles. Yeast two-hybrid results showed that ZaMYB86 interacted with ZaMYB5. Furthermore, ZaMYB5 was highly homologous to AtMYB5, a transcription factor that regulated trichomes development, in MYB DNA binding domain. Taken together, these results indicated that ZaMYB86 and ZaMYB5 act together to regulate the formation of prickles in Z. armatum. Our findings provided a new perspective for revealing the molecular mechanism of prickly formation.
竹叶花椒是一种重要的经济树种。皮刺是一种具有特殊形态的毛状体，竹叶花椒叶片上有大量皮刺，严重制约了竹叶花椒产业的发展。本研究以竹叶花椒栽培品种‘竹叶’（ZY）及其芽变品种‘荣昌无刺’（WC）（一种皮刺较少的突变品种）不同发育阶段的叶片为材料，对转录组测序数据进行分析。在样本中总共鉴定出96931个差异表达基因（DEG），其中1560个是可能参与激素代谢的候选DEG。ZY叶片中茉莉酸（JA）、生长素和细胞分裂素（CK）植物激素的含量显著高于WC叶片。结合加权基因共表达网络分析，鉴定出8个基因（MYC、IAA、ARF、CRE/AHK、PP2C、ARR - A、AOS和LOX），包括25个转录本，它们可能影响这三种激素的代谢并间接参与皮刺的形成。结合其他植物中成功报道的调控毛状体形成的蛋白质，通过本地Blast和系统发育树分析鉴定出R2R3 MYB家族的转录因子ZaMYB86，其可能调控竹叶花椒皮刺的形成。在突变型拟南芥中过表达ZaMYB86导致拟南芥叶片毛状体减少，进一步证实ZaMYB86参与皮刺的形成。酵母双杂交结果表明ZaMYB86与ZaMYB5相互作用。此外，ZaMYB5在MYB DNA结合结构域与调控毛状体发育的转录因子AtMYB5高度同源。综上所述，这些结果表明ZaMYB86和ZaMYB5共同作用调控竹叶花椒皮刺的形成。我们的研究结果为揭示皮刺形成的分子机制提供了新的视角。
