基于WGCNA的甘蔗细胞壁建成和糖分积累调控网络分析

2025-08-18颜宁王茂瑶李欣茹沈银娟李鸣张木清黄江锋

热带作物学报 2025年7期

摘" 要：甘蔗是重要的糖料作物和能源作物，糖分积累和细胞壁建成是其生长发育中的重要生物学过程。本研究以甘蔗品种新台糖22号为试验材料，采集其第1、3、5节叶片，第1、3、5、7、11、17节间茎髓和第3、5、7、11、17节间茎皮进行转录组测序。对获得的42份转录组数据利用WGCNA构建基因共表达矩阵，获得34个共表达模块。其中鉴定到与第1节叶片、第7节间茎髓和第5节间茎皮特异显著正相关的midnightblue、purple和magenta模块，KEGG代谢通路和GO功能富集分析表明这些模块参与了其组织中特定的生物学过程。Blue、yellow、turquoise和black模块分别主要在叶、幼髓、幼嫩节间和茎皮中表达，最终在blue模块中挖掘到参与光合作用的关键酶，包括LFNR1、PSAK、PETE、PSAN和NADP-ME4等，这些酶对甘蔗糖分的产生及积累十分关键。在yellow模块中，构建以SUS4为核心的蔗糖代谢网络，包括SWEET2等一系列与糖转运相关的酶和蛋白，证实了茎髓是甘蔗运输和储藏蔗糖的主要场所。在turquoise模块中，鉴定到可能参与初生细胞壁合成与修饰的糖蛋白和酶；调控次生细胞壁生物合成的转录因子NST1与其他修饰细胞壁的酶富集在black模块中，表明该模块可能参与茎皮的细胞壁沉积，为甘蔗提供机械强度与防御外界胁迫的屏障。以上结果为研究甘蔗糖分积累和细胞壁建成的调控网络提供重要参考。

关键词：甘蔗；WGCNA；糖分积累；细胞壁；转录组；调控网络中图分类号：S566.1 """""文献标志码：A

Unraveling the Complex Regulatory Networks Controlling Sugarcane Cell Wall Synthesis and Sugar Content via WGCNA

YAN Ning¹， WANG Maoyao¹， LI Xinru¹， SHEN Yinjuan¹， LI Ming²， ZHANG Muqing¹， HUANG Jiangfeng^1*

1. College of Agriculture， Guangxi University / State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources / Guangxi Key Laboratory of Sugarcane Biology， Nanning， Guangxi 530004， China; 2. Sugarcane Research Institute， Guangxi Academy of Agricultural Sciences， Nanning， Guangxi 530007， China

Abstract： Sugarcane is a crucial crop for both sugar and bioenergy production， with sugar accumulation and cell wall formation being critical biological processes during its growth and development. This study employed transcriptome sequencing on the ROC22 sugarcane variety， collecting samples from leaves at the 1^st， 3^rd， and 5^th nodes， bark tissues at the 3^rd， 5^th， 7^th， 11^th， and 17^th internodes， and pith tissues at the 1^st， 3^rd， 5^th， 7^th， 11^th， and 17^th internodes. A comprehensive analysis of 42 transcriptome datasets using Weighted Gene Co-expression Network Analysis （WGCNA） revealed 34 distinct co-expression modules. Notably， the midnight blue， purple， and magenta modules demonstrated significant and specific correlations with the 1^st node leaf， 7^th internode pith， and 5^th internode bark， respectively. KEGG and GO enrichment analyses indicated that the modules participated in tissue-specific biological processes. The blue， yellow， turquoise， and black modules were primarily expressed in leaves， young pith， immature internodes， and bark， respectively. Within the blue module， key enzymes implicated in photosynthesis were identified， such as LFNR1， PSAK， PETE， PSAN， and NADP-ME4， which are essential for the initial production and accumulation of sugar in sugarcane. The yellow module featured a sucrose metabolism network centered on SUS4， including SWEET2 and an array of sugar transport-related enzymes and proteins， suggesting that the pith serves as the primary site for sugar transport and storage in sugarcane. The turquoise module contained glycoproteins and enzymes potentially involved in the synthesis and modification of the primary cell wall. Meanwhile， transcription factor NST1， which regulates secondary cell wall biosynthesis， along with other cell wall-modifying enzymes in the black module， may contribute to cell wall deposition in the cortex， providing mechanical strength and a barrier against external stresses for sugarcane. The findings would provide important references for studying the regulatory networks of sugar accumulation and cell wall formation in sugarcane.