Zhang Mingyue, Li Xiaohan, Wang Xiao, Jiang Shuzhen, Zhang Junli, Sun Mingfei, Zhou Zixian, Zhang Jinxiao, Li Mengyao, Lv Yanxiao, Qi Enlong, Tian Ziang, Zhu Hongjie, Zhang Xuebin, Zhao Xiangyu, Xu Changcheng, Lübberstedt Thomas, Zhang Xiansheng, Yang Xuerong, Zhou Chao, Liu Hongjun
State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, Shandong, China.
State Key Laboratory of Crop Stress Adaptation and Improvement, Henan Joint International Laboratory for Crop Multi-Omics Research, School of Life Sciences, Henan University, Kaifeng, China.
Plant Biotechnol J. 2025 Jul;23(7):2449-2463. doi: 10.1111/pbi.70061. Epub 2025 Mar 28.
Maize is a key biomass resource with wide agricultural applications. Anthocyanins, potent antioxidants, offer health benefits like reducing oxidative stress. The biosynthesis of anthocyanins competes with that of lignin for shared metabolic precursors, which can lead to trade-offs in plant growth and feed quality. Higher lignin content can decrease silage digestibility, posing challenges for livestock feed. The maize brown midrib 6 (bm6) mutant, known for reduced lignin, has an unclear genetic basis. Here, we identify ZmGCH1 as the candidate gene for bm6 through fine mapping. Mutations in ZmGCH1 shift precursors from lignin to anthocyanin biosynthesis. Furthermore, we show that ZmGCH1 interacts with ZmPEBP15 to modulate chalcone synthase activity, thereby stabilizing the allocation of precursors between lignin and anthocyanin pathways. To evaluate the practical implications of our findings, we introduced the bm6 mutation into Zhengdan958 and Xianyu335. In vitro rumen digestion assays confirmed that the introduction of the bm6 mutation significantly improved silage digestibility. This discovery not only holds great potential for enhancing silage digestibility but also provides a broader strategy for optimizing maize production to better meet the increasing demands of both the food and livestock feed.
玉米是一种具有广泛农业应用的关键生物质资源。花青素是一种强大的抗氧化剂，具有降低氧化应激等健康益处。花青素的生物合成与木质素的生物合成竞争共享的代谢前体，这可能导致植物生长和饲料质量的权衡。较高的木质素含量会降低青贮饲料的消化率，给家畜饲料带来挑战。玉米棕色中脉6（bm6）突变体以木质素含量降低而闻名，但其遗传基础尚不清楚。在这里，我们通过精细定位确定ZmGCH1为bm6的候选基因。ZmGCH1中的突变将前体从木质素生物合成转移到花青素生物合成。此外，我们表明ZmGCH1与ZmPEBP15相互作用以调节查尔酮合酶活性，从而稳定木质素和花青素途径之间前体的分配。为了评估我们研究结果的实际意义，我们将bm6突变引入郑单958和先玉335。体外瘤胃消化试验证实，引入bm6突变显著提高了青贮饲料的消化率。这一发现不仅在提高青贮饲料消化率方面具有巨大潜力，而且为优化玉米生产以更好地满足食品和家畜饲料不断增长的需求提供了更广泛的策略。
