PDF(Pubmed)
Abstract：
Pinellia ternata is a medicinal plant that has important pharmacological value, and the bulbils serve as the primary reproductive organ; however, the mechanisms underlying bulbil initiation remain unclear. Here, we characterized bulbil development via histological, transcriptomic, and targeted metabolomic analyses to unearth the intricate relationship between hormones, genes, and bulbil development. The results show that the bulbils initiate growth from the leaf axillary meristem (AM). In this stage, jasmonic acid (JA), abscisic acid (ABA), isopentenyl adenosine (IPA), and salicylic acid (SA) were highly enriched, while indole-3-acetic acid (IAA), zeatin, methyl jasmonate (MeJA), and 5-dexoxystrigol (5-DS) were notably decreased. Through OPLS-DA analysis, SA has emerged as the most crucial factor in initiating and positively regulating bulbil formation. Furthermore, a strong association between IPA and SA was observed during bulbil initiation. The transcriptional changes in IPT (Isopentenyltransferase), CRE1 (Cytokinin Response 1), A-ARR (Type-A Arabidopsis Response Regulator), B-ARR (Type-B Arabidopsis Response Regulator), AUX1 (Auxin Resistant 1), ARF (Auxin Response Factor), AUX/IAA (Auxin/Indole-3-acetic acid), GH3 (Gretchen Hagen 3), SAUR (Small Auxin Up RNA), GA2ox (Gibberellin 2-oxidase), GA20ox (Gibberellin 20-oxidase), AOS (Allene oxide synthase), AOC (Allene oxide cyclase), OPR (Oxophytodienoate Reductase), JMT (JA carboxy l Methyltransferase), COI1 (Coronatine Insensitive 1), JAZ (Jasmonate ZIM-domain), MYC2 (Myelocytomatosis 2), D27 (DWARF27), SMAX (Suppressor of MAX2), PAL (Phenylalanine Ammonia-Lyase), ICS (Isochorismate Synthase), NPR1 (Non-expressor of Pathogenesis-related Genes1), TGA (TGACG Sequence-specific Binding), PR-1 (Pathogenesis-related), MCSU (Molybdenium Cofactor Sulfurase), PP2C (Protein Phosphatase 2C), and SnRK (Sucrose Non-fermenting-related Protein Kinase 2) were highly correlated with hormone concentrations, indicating that bulbil initiation is coordinately controlled by multiple phytohormones. Notably, eight TFs (transcription factors) that regulate AM initiation have been identified as pivotal regulators of bulbil formation. Among these, WUS (WUSCHEL), CLV (CLAVATA), ATH1 (Arabidopsis Thaliana Homeobox Gene 1), and RAX (Regulator of Axillary meristems) have been observed to exhibit elevated expression levels. Conversely, LEAFY demonstrated contrasting expression patterns. The intricate expression profiles of these TFs are closely associated with the upregulated expression of KNOX(KNOTTED-like homeobox), suggesting a intricate regulatory network underlying the complex process of bulbil initiation. This study offers a profound understanding of the bulbil initiation process and could potentially aid in refining molecular breeding techniques specific to P. ternata.
摘要：
半夏是一种具有重要药理价值的药用植物,球茎是主要的生殖器官；然而，Bulbil启动的潜在机制仍不清楚.这里,我们通过组织学表征了球茎发育，转录组，和有针对性的代谢组学分析来揭示激素之间的复杂关系，基因，和bulbil开发。结果表明，球茎从叶腋生分生组织（AM）开始生长。在这个阶段,茉莉酸（JA），脱落酸（ABA），异戊烯基腺苷(IPA),和水杨酸（SA）高度富集，而吲哚-3-乙酸（IAA），zeatin,茉莉酸甲酯（MeJA），和5-右旋曲醇（5-DS）显着降低。通过OPLS-DA分析,SA已成为启动和积极调节球茎形成的最关键因素。此外，在Bulbil启动期间观察到IPA和SA之间的强关联.IPT（异戊烯基转移酶）的转录变化，CRE1（细胞分裂素反应1），A-ARR(A型拟南芥响应调节剂),B-ARR（B型拟南芥响应调节剂），AUX1（抗生长素1），ARF（生长素反应因子），AUX/IAA（生长素/吲哚-3-乙酸），GH3(GretchenHagen3),SAUR（小生长素RNA），GA2ox（赤霉素2-氧化酶），GA20ox（赤霉素20-氧化酶），AOS（丙二烯氧合酶），AOC（氧化丙烯环化酶），OPR（草酸二烯酸还原酶），JMT（JA羧基甲基转移酶），COI1（冠状病毒不敏感1），JAZ(JasmonateZIM-domain),MYC2（骨髓细胞瘤病2），D27(DWARF27),SMAX（MAX2的抑制器），PAL(苯丙氨酸氨裂解酶),ICS（异氯酸盐合成酶），NPR1(发病相关基因的非表达体),TGA（TGACG序列特异性结合），PR-1（发病相关），MCSU（钼辅因子硫化酶），PP2C（蛋白磷酸酶2C），和SnRK（蔗糖非发酵相关蛋白激酶2）与激素浓度高度相关，表明bulbil的启动受多种植物激素的协调控制。值得注意的是,调节AM起始的八种TFs（转录因子）已被确定为bulbil形成的关键调节因子。其中,WUS(WUSCHEL),CLV(CLAVATA),ATH1(拟南芥同源异型盒基因1),并且已经观察到RAX(腋下分生组织的调节剂)表现出升高的表达水平。相反，LEAFY表现出相反的表达模式。这些TF的复杂表达谱与KNOX（类似KNOTTED的同源盒）的上调表达密切相关，暗示了一个复杂的监管网络，其背后是Bulbil启动的复杂过程。这项研究提供了对bulbil起始过程的深刻理解，并可能有助于完善特定于P.ternata的分子育种技术。
