Wu Xiaojie, Yang Lingfang, Han Jinbo, Liu Hanqing, Chen Gaokun, Wang Haoyuan, Feng Xingru, Zhang Wan, Liu Kangping, Zhang Zemin
State Key Laboratory for Conservation and Utilization of Subtropical Agro‑Bioresources, Guangdong Provincial Key Laboratory of Plant Molecular Breeding, College of Agriculture, South China Agricultural University, Guangzhou, 510642, China.
Guangdong Yueliang Seed Industry Co., Ltd, Zhanjiang, China.
BMC Genomics. 2025 Sep 1;26(1):792. doi: 10.1186/s12864-025-11977-0.
Plants have evolved the ability to produce specialized metabolites as a defense mechanism against biotic and abiotic stressors, with flavonoid-mediated defense responses playing a crucial role in this process. Diverse flavonoids are present in various rice-grown resources, and they confer tolerance to different environmental conditions, including high temperature stress. Elucidating the differences in these flavonoids is essential for breeding improved rice varieties with enhanced tolerance to adverse environments. In a previous study, we isolated a dominant rice mutant generated by T-DNA insertion and christened it rolled and erect leaf 1 (hereafter rel1-D), initially identified for its enhanced tolerance to drought stress and its involvement in the regulation of leaf rolling and erectness. In this study, we utilized ZH11 and the rel1-D mutant as experimental materials to compare the expression profiles of genes and metabolites involved in the flavonoid pathway and high-temperature tolerance.
In our previous study, we generated a dominant mutant rel1-D in the ZH11 rice background via T-DNA insertion. Upon exposure to high-temperature stress followed by a recovery period, we observed that all ZH11 plants succumbed to the stress, whereas nearly 50% of the rel1-D mutants survived. Comprehensive transcriptomic and metabolomic analyses revealed 1,184 differentially expressed genes (DEGs) and 126 differentially abundant metabolites (DAMs) between the two genotypes. Notably, the majority of these differentially expressed genes and metabolites were enriched in the phenylalanine and flavonoid biosynthetic pathways in the rel1-D mutant. Specifically, the expression levels of key genes involved in flavonoid biosynthesis, including OsCHI, OsF3H, OsFLS, OsCHS, OsPAL, and Os4CL, were significantly upregulated in rel1-D, resulting in elevated levels of flavonoid compounds. Furthermore, we constructed a correlation network integrating phenotypic traits with the identified genes and metabolites. Our analysis indicated that the metabolism of flavonoids and phenolic compounds in leaves was positively correlated, whereas both were negatively correlated with yield-related traits.
Potential genes regulated by ROLLED AND ERECT LEAF1 (REL1) and flavonoid metabolites were identified. REL1 may affect the accumulation of flavonoid metabolites by regulating the expression of key genes in the flavonoid biosynthesis pathway to influence the heat tolerance of rice.
植物进化出了产生特殊代谢产物的能力，以此作为抵御生物和非生物胁迫的防御机制，其中类黄酮介导的防御反应在这一过程中起着关键作用。不同的类黄酮存在于各种水稻种植资源中，它们赋予水稻对不同环境条件的耐受性，包括高温胁迫。阐明这些类黄酮的差异对于培育对不利环境耐受性增强的改良水稻品种至关重要。在先前的一项研究中，我们分离出了一个由T-DNA插入产生的显性水稻突变体，并将其命名为卷叶直立叶1（以下简称rel1-D），最初因其对干旱胁迫的耐受性增强以及参与叶片卷曲和直立性的调节而被鉴定。在本研究中，我们以ZH11和rel1-D突变体作为实验材料，比较了类黄酮途径和高温耐受性相关基因及代谢产物的表达谱。
在我们先前的研究中，通过T-DNA插入在ZH11水稻背景中产生了显性突变体rel1-D。在暴露于高温胁迫并经过恢复期后，我们观察到所有ZH11植株都在胁迫中死亡，而近50%的rel1-D突变体存活了下来。全面的转录组学和代谢组学分析揭示了两种基因型之间有1184个差异表达基因（DEG）和126种差异丰富代谢产物（DAM）。值得注意的是，这些差异表达基因和代谢产物中的大多数在rel-D突变体中富集于苯丙氨酸和类黄酮生物合成途径。具体而言，参与类黄酮生物合成的关键基因，包括OsCHI、OsF3H、OsFLS、OsCHS、OsPAL和Os4CL的表达水平在rel1-D中显著上调，导致类黄酮化合物水平升高。此外，我们构建了一个将表型性状与已鉴定的基因和代谢产物整合在一起的相关网络。我们的分析表明，叶片中类黄酮和酚类化合物的代谢呈正相关，而两者均与产量相关性状呈负相关。
鉴定了由卷叶直立叶1（REL1）调控的潜在基因和类黄酮代谢产物。REL1可能通过调节类黄酮生物合成途径中关键基因的表达来影响类黄酮代谢产物的积累，从而影响水稻的耐热性。
