【摘要】 脱落酸(abscisic acid, ABA)是植物体内关键的激素，参与调控植物生长发育及逆境响应的全过程。9-顺式-环氧类胡萝卜素双加氧酶(nine-cis-epoxycarotenoid dioxygenase, NCED)作为ABA合成途径的核心限速酶，直接决定其生物合成效率与含量。鉴定并分析黄秋葵(Hibiscus esculentus)中NCED基因，有助于揭示ABA调控黄秋葵果荚衰老的分子机制。本研究对黄秋葵NCED基因进行鉴定及生物信息学分析。结果显示，黄秋葵HeNCED基因(GenBank No. PZ350883)全长2 196 bp，开放阅读框为1 803 bp，编码600个氨基酸。该蛋白定位于细胞质，为酸性、亲水和不稳定蛋白。序列相似性分析显示，其编码的蛋白与异常棉(Gossypium anomala)、雷蒙德氏棉(G. raimondii)、亚洲棉(G. arboreum)、木槿(H. syriacus)中同源蛋白序列相似度均高于88%，具有高度的保守性。对外源ABA、NDGA处理不同发育阶段和采后果荚的qPCR表达分析发现，HeNCED基因表达量与ABA含量显著正相关(P<0.01)。推测在黄秋葵果荚中，HeNCED基因通过调控ABA合成进而调控次生壁的加厚。本研究初步揭示了HeNCED基因在黄秋葵果荚老化过程中的分子机制，可为黄秋葵的分子育种、栽培生产和采后贮藏保鲜研究提供理论依据和基因资源。更多还原

【Abstract】 Abscisic acid(ABA) serves as a pivotal hormone in plants, regulating the entire process of plant growth, development, and stress responses. Nine-cis-epoxycarotenoid dioxygenase(NCED) acts as the ratelimiting enzyme in ABA biosynthesis, directly determining its biosynthetic efficiency and content. The identification and analysis of the NCED gene in Hibiscus esculentus are crucial for elucidating the mechanism of ABA-mediated regulation of pod senescence. In this study, the HeNCED gene in H. esculentus was identified and analyzed using bioinformatics. The results revealed that the full length of HeNCED gene(GenBank No. PZ350883) was 2 196 bp, with an open reading frame(ORF) of 1 803 bp encoding 600 amino acids. The protein was localized in the cytoplasm, exhibiting acidic, hydrophilic, and unstable properties.Sequence similarity analysis showed over 88% identity with homologous proteins from Gossypium anomalum,G. raimondii, G. arboreum, and H. syriacus, indicating high conservation. qPCR analysis of pod samples at different developmental stages and post-harvest treated with exogenous ABA and nordihydroguaiaretic acid(NDGA) demonstrated a significant positive correlation between HeNCED expression and ABA content(P<0.01). It was hypothesized that HeNCED regulated secondary wall thickening in H. esculentus pods via modulating ABA synthesis. This study preliminarily revealed the molecular mechanism of HeNCED in Hibiscus esculentus pod aging, which can provide a theoretical basis and genetic resources for molecular breeding, cultivation, and post-harvest storage of H esculentus.更多还原