College of Bioscience and Biotechnology, Shenyang Agricultural University, Shenyang 110866, China.
Int J Mol Sci. 2024 Aug 23;25(17):9161. doi: 10.3390/ijms25179161.
Plants are an important source for the discovery of novel natural growth regulators. We used activity screening to demonstrate that treatment of Nipponbare seeds with 25 μg/mL isopimaric acid significantly increased the resulting shoot length, root length, and shoot weight of rice seedlings by 11.37 ± 5.05%, 12.96 ± 7.63%, and 27.98 ± 10.88% and that it has a higher activity than Gibberellin A3 (GA) at the same concentration. A total of 213 inbred lines of different rice lineages were screened, and we found that isopimaric acid had different growth promotional activities on rice seedlings of different varieties. After induction with 25 μg/mL isopimaric acid, 15.02% of the rice varieties tested showed increased growth, while 15.96% of the varieties showed decreased growth; the growth of the remaining 69.02% did not show any significant change from the control. In the rice varieties showing an increase in growth, the shoot length and shoot weight significantly increased, accounting for 21.88% and 31.25%. The root length and weight significantly increased, accounting for 6.25% and 3.13%. Using genome-wide association studies (GWASs), linkage disequilibrium block, and gene haplotype significance analysis, we identified single nucleotide polymorphism (SNP) signals that were significantly associated with the length and weight of shoots on chromosomes 2 and 8, respectively. After that, we obtained 17 candidate genes related to the length of shoots and 4 candidate genes related to the weight of shoots. Finally, from the gene annotation data and gene tissue-specific expression; two genes related to this isopimaric acid regulation phenotype were identified as () on chromosome 2 and () on chromosome 8. Subcellular localization analysis indicated that OsASC1 was expressed in the plasma membrane and the nuclear membrane, while OsBUD13 was expressed in the nucleus. Further RT-qPCR analysis showed that the relative expression levels of the resistance gene and the antibody protein gene decreased significantly following treatment with 25 μg/mL isopimaric acid. These results suggest that isopimaric acid may inhibit defense pathways in order to promote the growth of rice seedlings.
植物是发现新型天然生长调节剂的重要来源。我们使用活性筛选方法证明，用 25μg/mL 的异海松酸处理粳稻种子可使水稻幼苗的茎长、根长和地上部鲜重分别显著增加 11.37±5.05%、12.96±7.63%和 27.98±10.88%，其活性高于相同浓度的赤霉素 A3（GA）。我们对 213 个不同水稻谱系的近交系进行了筛选，发现异海松酸对不同品种的水稻幼苗具有不同的生长促进活性。用 25μg/mL 异海松酸诱导后，所测试的 15.02%的水稻品种表现出生长增加，而 15.96%的品种表现出生长减少；其余 69.02%的品种没有从对照中表现出任何显著变化。在表现出生长增加的水稻品种中，茎长和地上部鲜重显著增加，分别占 21.88%和 31.25%。根长和根重显著增加，分别占 6.25%和 3.13%。利用全基因组关联研究（GWASs）、连锁不平衡块和基因单倍型显著性分析，我们在第 2 号和第 8 号染色体上分别鉴定到与地上部长度和重量显著相关的单核苷酸多态性（SNP）信号。之后，我们获得了 17 个与地上部长度相关的候选基因和 4 个与地上部重量相关的候选基因。最后，从基因注释数据和基因组织特异性表达中，鉴定到与该异海松酸调控表型相关的两个基因分别为 （）在第 2 号染色体上和 （）在第 8 号染色体上。亚细胞定位分析表明，OsASC1 表达于质膜和核膜，而 OsBUD13 表达于细胞核。进一步的 RT-qPCR 分析表明，用 25μg/mL 异海松酸处理后，抗性基因 和抗体蛋白基因 的相对表达水平显著下降。这些结果表明，异海松酸可能通过抑制防御途径来促进水稻幼苗的生长。
