丛生型巨龙竹愈伤组织分化及其与糖和激素相关的生理作用。

Shoot differentiation from Dendrocalamus brandisii callus and the related physiological roles of sugar and hormones during shoot differentiation.

机构信息

Faculty of Life Sciences, Southwest Forestry University, Kunming 650224, China.

Bamboo Research Institute, Nanjing Forestry University, Nanjing 210037, China.

出版信息

Tree Physiol. 2023 Jul 9;43(7):1159-1186. doi: 10.1093/treephys/tpad039.

DOI:10.1093/treephys/tpad039

PMID:36988419

Abstract

Only a few calli regeneration systems of bamboos were successfully established, which limited the research on the physiological mechanism of callus differentiation. In this study, we successfully established the callus differentiation systems of Dendrocalamus brandisii (Munro) via seeds. The results showed that the best medium for the callus induction of D. brandisii seeds was basal Murashige and Skoog (1962) (MS) media amended with 5.0 mg l-1 2,4-D and 0.5 mg l-1 kinetin (KT), and the optimal medium for shoot differentiation was the basal MS media supplemented with 4.0 mg l-1 6-benzylaminopurine (6-BA) and 0.5 mg l-1 1-Naphthaleneacetic acid (NAA). Callus tissues had apparent polarity in cell arrangement and developed their own meristematic cell layers. Alpha-amylase (α-amylase), starch phosphorylase (STP) and sucrose synthase (SUSY) played a dominant role in carbohydrate degradation in callus during shoot differentiation. The pentose phosphate pathway (PPP) and TCA pathways were up-regulated in the shoot-differentiated calli. The dynamics of 6-BA and KT contents in calli were consistent with their concentrations applied in medium. Indoleacetic acid (IAA) synthesis and the related signal transduction were down-regulated, whereas the endogenous CTK contents were up-regulated by the exogenous cytokinin (CTK) application in shoot-differentiated calli, and their related synthesis, transport and signal transduction pathways were also up-regulated. The down-regulated signal transduction pathways of IAA and abscisic acid (ABA) revealed that they did not play the key role in the shoot differentiation of bamboos. Gibberellins (GAs) also played a role in shoot differentiation based on the down-regulation of DELLA and the up-regulation of PIF4 genes. The overexpression of DbSNRK2 and DbFIF4 genes further confirmed the negative role of ABA and the positive role of GAs in shoot differentiation.

摘要

仅有少数几种竹子的愈伤组织再生系统成功建立，这限制了对愈伤组织分化生理机制的研究。本研究通过种子成功建立了绿竹（Munro）的愈伤组织分化系统。结果表明，D. brandisii 种子愈伤组织诱导的最佳培养基是基础 Murashige 和 Skoog（1962）（MS）培养基，添加 5.0 mg·l-1 2,4-D 和 0.5 mg·l-1 激动素（KT），最佳的芽分化培养基是基础 MS 培养基，添加 4.0 mg·l-1 6-苄基氨基嘌呤（6-BA）和 0.5 mg·l-1 1-萘乙酸（NAA）。愈伤组织在细胞排列上具有明显的极性，并发育出自己的分生组织细胞层。α-淀粉酶（α-amylase）、淀粉磷酸化酶（STP）和蔗糖合酶（SUSY）在芽分化过程中在愈伤组织的碳水化合物降解中起主导作用。戊糖磷酸途径（PPP）和 TCA 途径在芽分化的愈伤组织中被上调。6-BA 和 KT 含量在愈伤组织中的动态与它们在培养基中的浓度一致。吲哚乙酸（IAA）的合成及其相关信号转导下调，而外源性细胞分裂素（CTK）在芽分化的愈伤组织中应用上调了内源性 CTK 含量，其相关合成、运输和信号转导途径也被上调。IAA 和脱落酸（ABA）的下调信号转导途径表明它们在竹子的芽分化中不起关键作用。赤霉素（GAs）也通过下调 DELLA 和上调 PIF4 基因在芽分化中发挥作用。DbSNRK2 和 DbFIF4 基因的过表达进一步证实了 ABA 的负作用和 GAs 在芽分化中的正作用。