Huang Yanzhong, Wu Juanzi, Lin Jianyu, Liu Zhiwei, Mao Zhengfeng, Qian Chen, Zhong Xiaoxian
National Forage Breeding Innovation Base (JAAS), Institute of Animal Science, Jiangsu Academy of Agricultural Sciences, Key Laboratory for Saline-Alkali Soil Improvement and Utilization (Coastal Saline-Alkali Lands), Ministry of Agriculture and Rural Affairs, Nanjing 210014, China.
National Center for Soybean Improvement, Key Laboratory of Biology and Genetics and Breeding for Soybean, Ministry of Agriculture, State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China.
Plants (Basel). 2024 May 14;13(10):1352. doi: 10.3390/plants13101352.
The degree of forage lignification is a key factor affecting its digestibility by ruminants such as cattle and sheep. Sudan grass ( S.) is a high-quality sorghum forage, and its lignocellulose is mostly stored in the secondary cell wall. However, the secondary cell wall synthesis mechanism of Sudan grass has not yet been studied in depth. To further study the secondary cell wall synthesis mechanism of Sudan grass using established transcriptome data, this study found that , a homologous gene of , is related to the secondary cell wall synthesis of Sudan grass. Accordingly, we constructed a -overexpressing line of to investigate the function of the gene in secondary cell wall synthesis. The results showed that the overexpression of the gene could significantly increase the lignin content of . Based on subcellular localization analysis, CcNAC6 is found in the nucleus. In addition, yeast two-hybridization screening showed that CcCP1, associated with secondary cell wall synthesis, can interact with CcNAC6. Therefore, the above results indicate that has a positive regulatory effect on the secondary cell wall synthesis of Sudan grass, and it is speculated that CcNAC6 may be the main regulator of the secondary cell wall synthesis of Sudan grass through its interaction with another regulatory protein, CcCP1. This study provides a theoretical basis and new genetic resources for the creation of new Sudan grass germplasm with a low lignin content.
牧草木质化程度是影响牛羊等反刍动物对其消化率的关键因素。苏丹草是一种优质高粱属牧草，其木质纤维素大多储存于次生细胞壁中。然而，苏丹草次生细胞壁的合成机制尚未得到深入研究。为利用已有的转录组数据进一步研究苏丹草次生细胞壁的合成机制，本研究发现， （ 的同源基因）与苏丹草次生细胞壁的合成有关。据此，我们构建了 的过表达株系，以研究 基因在次生细胞壁合成中的功能。结果表明， 基因的过表达可显著提高 的木质素含量。基于亚细胞定位分析，发现CcNAC6定位于细胞核。此外，酵母双杂交筛选表明，与次生细胞壁合成相关的CcCP1可与CcNAC6相互作用。因此，上述结果表明， 对苏丹草次生细胞壁的合成具有正向调控作用，推测CcNAC6可能通过与另一种调控蛋白CcCP1相互作用，成为苏丹草次生细胞壁合成的主要调控因子。本研究为创制低木质素含量的苏丹草新种质提供了理论依据和新的基因资源。
