Department of Biological Sciences, Institute for Life Sciences, Kangwon National University, Chuncheon, 24341, Korea.
Department of Life Science, Multidisciplinary Genome Institute, Hallym University, Chuncheon, 24252, Korea.
BMC Plant Biol. 2024 May 7;24(1):367. doi: 10.1186/s12870-024-05033-4.
The formation of shoots plays a pivotal role in plant organogenesis and productivity. Despite its significance, the underlying molecular mechanism of de novo regeneration has not been extensively elucidated in Capsicum annuum 'Dempsey', a bell pepper cultivar. To address this, we performed a comparative transcriptome analysis focusing on the differential expression in C. annuum 'Dempsey' shoot, callus, and leaf tissue. We further investigated phytohormone-related biological processes and their interacting genes in the C. annuum 'Dempsey' transcriptome based on comparative transcriptomic analysis across five species.
We provided a comprehensive view of the gene networks regulating shoot formation on the callus, revealing a strong involvement of hypoxia responses and oxidative stress. Our comparative transcriptome analysis revealed a significant conservation in the increase of gene expression patterns related to auxin and defense mechanisms in both callus and shoot tissues. Consequently, hypoxia response and defense mechanism emerged as critical regulators in callus and shoot formation in C. annuum 'Dempsey'. Current transcriptome data also indicated a substantial decline in gene expression linked to photosynthesis within regenerative tissues, implying a deactivation of the regulatory system governing photosynthesis in C. annuum 'Dempsey'.
Coupled with defense mechanisms, we thus considered spatial redistribution of auxin to play a critical role in the shoot morphogenesis via primordia outgrowth. Our findings shed light on shoot formation mechanisms in C. annuum 'Dempsey' explants, important information for regeneration programs, and have broader implications for precise molecular breeding in recalcitrant crops.
芽的形成在植物器官发生和生产力中起着关键作用。尽管其意义重大，但在甜椒品种“Dempsey”中，茎芽再生的潜在分子机制尚未得到广泛阐明。为了解决这个问题，我们进行了比较转录组分析，重点研究了 C. annuum 'Dempsey'芽、愈伤组织和叶片组织中的差异表达。我们进一步根据跨五个物种的比较转录组分析，研究了与植物激素相关的生物过程及其在 C. annuum 'Dempsey'转录组中的相互作用基因。
我们提供了一个关于在愈伤组织上调节芽形成的基因网络的全面视图，揭示了缺氧反应和氧化应激的强烈参与。我们的比较转录组分析显示，在愈伤组织和芽组织中，与生长素和防御机制相关的基因表达模式的增加具有显著的保守性。因此，缺氧反应和防御机制成为“Dempsey”甜椒愈伤组织和芽形成的关键调节因子。目前的转录组数据还表明，与再生组织中光合作用相关的基因表达大量下降，这意味着在“Dempsey”甜椒中，调节光合作用的调控系统失活。
我们认为，与防御机制一起，生长素的空间再分配在通过原基生长来调节芽形态发生中起着关键作用。我们的发现为“Dempsey”甜椒外植体的芽形成机制提供了启示，这是再生计划的重要信息，对难繁殖作物的精确分子育种具有更广泛的意义。
