College of Life Sciences, South China Agricultural University, Guangzhou 510642, China.
Cash Crops Research Institute, Hubei Academy of Agricultural Sciences, Wuhan 430064, China.
Int J Mol Sci. 2022 Aug 3;23(15):8620. doi: 10.3390/ijms23158620.
Photosynthesis is one of the most important factors in mulberry growth and production. To study the photosynthetic regulatory network of mulberry we sequenced the transcriptomes of two high-yielding (E1 and E2) and one low-yielding (H32) mulberry genotypes at two-time points (10:00 and 12:00). Re-annotation of the mulberry genome based on the transcriptome sequencing data identified 22,664 high-quality protein-coding genes with a BUSCO-assessed completeness of 93.4%. A total of 6587 differentially expressed genes (DEGs) were obtained in the transcriptome analysis. Functional annotation and enrichment revealed 142 out of 6587 genes involved in the photosynthetic pathway and chloroplast development. Moreover, 3 out of 142 genes were further examined using the VIGS technique; the leaves of - and -silenced plants were markedly yellowed or even white, and the leaves of -silenced plants showed a wrinkled appearance. The expression levels of the ensiled plants were reduced, and the levels of chlorophyll b and total chlorophyll were lower than those of the control plants. Co-expression analysis showed that was co-expressed with and ; was co-expressed with , , and ; was mainly co-expressed with , , and . Protein interaction network prediction revealed that MaCLA1 was associated with RPE, TRA2, GPS1, and DXR proteins; MaTHIC was associated with TH1, PUR5, BIO2, and THI1; MaPKP2 was associated with ENOC, LOS2, and PGI1. This study offers a useful resource for further investigation of the molecular mechanisms involved in mulberry photosynthesis and preliminary insight into the regulatory network of photosynthesis.
光合作用是桑树生长和生产的最重要因素之一。为了研究桑树的光合作用调控网络，我们在两个时间点（10：00 和 12：00）对两个高产（E1 和 E2）和一个低产（H32）桑树基因型进行了转录组测序。基于转录组测序数据对桑树基因组进行重新注释，鉴定出 22664 个高质量的蛋白质编码基因，具有 93.4%的 BUSCO 评估完整性。在转录组分析中获得了 6587 个差异表达基因（DEGs）。功能注释和富集分析显示，在 6587 个基因中有 142 个基因参与光合作用途径和叶绿体发育。此外，使用 VIGS 技术进一步研究了 3 个基因；-和-silenced 植物的叶子明显变黄甚至变白，-silenced 植物的叶子出现皱缩。沉默植物的表达水平降低，叶绿素 b 和总叶绿素的水平低于对照植物。共表达分析表明，与和共表达；与、和共表达；主要与、和共表达。蛋白质互作网络预测表明，MaCLA1 与 RPE、TRA2、GPS1 和 DXR 蛋白相关；MaTHIC 与 TH1、PUR5、BIO2 和 THI1 相关；MaPKP2 与 ENOC、LOS2 和 PGI1 相关。本研究为进一步研究桑树光合作用的分子机制提供了有用的资源，并初步探讨了光合作用的调控网络。
