Laboratório de Melhoramento Genético Vegetal - LMGV, Universidade Estadual do Norte Fluminense Darcy Ribeiro-UENF, Campos dos Goytacazes, 28.013-602, Brazil.
Laboratório de Biotecnologia - LBT, Universidade Estadual do Norte Fluminense Darcy Ribeiro-UENF, Campos dos Goytacazes, 28.013-602, Brazil.
Sci Rep. 2024 Apr 17;14(1):8867. doi: 10.1038/s41598-024-59306-x.
Papaya (Carica papaya) is a trioecious species with female, male, and hermaphrodite plants. Given the sex segregation, selecting hermaphroditic plants is vital for orchard establishment due to their greater commercial value. However, selecting hermaphrodite plants through sexing is laborious and costly. Moreover, environmental stressors can exacerbate the issue by potentially inducing abnormal flower development, thus affecting fruit quality. Despite these challenges, the molecular mechanisms governing sex development in papaya remain poorly understood. Thus, this study aimed to identify proteins associated with sex development in female and hermaphrodite flowers of papaya through comparative proteomic analysis. Proteins from flower buds at the early and late developmental stages of three papaya genotypes (UENF-CALIMAN 01, JS12, and Sunrise Solo 72/12) were studied via proteomic analysis via the combination of the shotgun method and nanoESI-HDMS technology. In buds at an early stage of development, 496 (35.9%) proteins exhibited significantly different abundances between sexes for the SS72/12 genotype, 139 (10%) for the JS12 genotype, and 165 (11.9%) for the UC-01 genotype. At the final stage of development, there were 181 (13.5%) for SS72/12, 113 (8.4%) for JS12, and 125 (9.1%) for UC-01. The large group of differentially accumulated proteins (DAPs) between the sexes was related to metabolism, as shown by the observation of only the proteins that exhibited the same pattern of accumulation in the three genotypes. Specifically, carbohydrate metabolism proteins were up-regulated in hermaphrodite flower buds early in development, while those linked to monosaccharide and amino acid metabolism increased during late development. Enrichment of sporopollenin and phenylpropanoid biosynthesis pathways characterizes hermaphrodite samples across developmental stages, with predicted protein interactions highlighting the crucial role of phenylpropanoids in sporopollenin biosynthesis for pollen wall formation. Most of the DAPs played key roles in pectin, cellulose, and lignin synthesis and were essential for cell wall formation and male flower structure development, notably in the pollen coat. These findings suggest that hermaphrodite flowers require more energy for development, likely due to complex pollen wall formation. Overall, these insights illuminate the molecular mechanisms of papaya floral development, revealing complex regulatory networks and energetic demands in the formation of male reproductive structures.
番木瓜（Carica papaya）是一种雌雄同体的物种，具有雌性、雄性和雌雄同体植物。鉴于性别隔离，选择雌雄同体植物对于果园的建立至关重要，因为它们具有更高的商业价值。然而，通过性别选择雌雄同体植物是劳动密集型和昂贵的。此外，环境胁迫因子可能通过潜在地诱导异常的花发育而使问题恶化，从而影响果实质量。尽管存在这些挑战，但番木瓜性别发育的分子机制仍知之甚少。因此，本研究旨在通过比较蛋白质组学分析鉴定与番木瓜雌、雄花性别发育相关的蛋白质。通过组合shotgun 方法和 nanoESI-HDMS 技术，对三个番木瓜基因型（UENF-CALIMAN 01、JS12 和 Sunrise Solo 72/12）的花蕾早期和晚期发育阶段的蛋白质进行了蛋白质组学分析。在早期发育阶段，SS72/12 基因型的 496 个（35.9%）蛋白质在性别间表现出显著差异，JS12 基因型的 139 个（10%），UC-01 基因型的 165 个（11.9%）。在发育的最后阶段，SS72/12 有 181 个（13.5%），JS12 有 113 个（8.4%），UC-01 有 125 个（9.1%）。性别间大量差异积累的蛋白质（DAP）与代谢有关，这表明只有在三个基因型中表现出相同积累模式的蛋白质才具有这种特性。具体而言，在早期发育过程中，雄花的碳水化合物代谢蛋白上调，而在后期发育过程中，与单糖和氨基酸代谢相关的蛋白增加。 sporopollenin 和苯丙素生物合成途径的富集特征是在整个发育阶段的雌雄同体样本中，预测的蛋白质相互作用突出了苯丙素在花粉壁形成中对 sporopollenin 生物合成的关键作用。大多数 DAPs 在果胶、纤维素和木质素合成中发挥关键作用，对细胞壁形成和雄性花结构发育至关重要，特别是在花粉涂层中。这些发现表明，雌雄同体花的发育需要更多的能量，这可能是由于复杂的花粉壁形成。总的来说，这些发现阐明了番木瓜花发育的分子机制，揭示了形成雄性生殖结构的复杂调控网络和能量需求。
