Increased endogenous gibberellin level inhibits root growth of Pinus massoniana Lamb. plantlets during long-term subculture
Increased endogenous gibberellin level inhibits root growth of Pinus massoniana Lamb. plantlets during long-term subculture
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DOI：
10.1007/s11627-020-10067-y
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发表时间：
2020-03
期刊：
影响因子：
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通讯作者：
Yin Wang;R. Yao
中科院分区：
文献类型：
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作者：
Yin Wang;R. Yao
本文研究了植物激素吲哚乙酸（IAA）和赤霉素（GA）对马尾松（Pinus massonianaLamb.）在长期继代培养过程中再生植株。6代（第1，第5，第10，第20，第30和第40次与40天，每个转移周期）的继代芽来自成熟和幼年外植体的特点是他们不同的生根能力。本试验以试管苗继代培养在含有吲哚乙酸（IAA）、萘乙酸（NAA）或赤霉素（GA）抑制剂多效唑（PBZ）的生根培养基上。此外，利用高效液相色谱法（HPLC）分析了在低浓度NAA培养基上生长的芽中的内源激素水平。20代苗内源IAA含量最高，生根能力也最强。但是，GA浓度在第40代芽中最高，表现出较差的生根能力。继代培养40代的试管苗，在含IAA的生根培养基上生根，生根数、苗长和成活率均有所提高。这表明IAA对不定芽和不定根的形成有积极的促进作用。PBZ促进离体培养的植株再生，但在高水平上抑制芽的伸长。此外，PBZ改善了长期（3至4年）传代培养后的体外培养性能。这些结果表明，高水平的内源GA对植株再生的抑制作用和适当水平的PBZ对P。马森尼亚。
In this study, we investigated the roles of the plant hormones indole-3-acetic acid (IAA) and gibberellin (GA) in regulatingPinus massonianaLamb. plantlet regeneration during long-termin vitrosubculture. Six generations (1st, 5th, 10th, 20th, 30th and 40th with 40 days for each transfer cycle) of subcultured shoots derived from mature and juvenile explants were characterised for their different rooting capacities. In the present experiment, shoots were subcultured on rooting medium containing indole-3-acetic acid (IAA), naphthaleneacetic acid (NAA) or gibberellin (GA) inhibitor (paclobutrazol, PBZ). In addition, high-performance liquid chromatography (HPLC) was used to analyse endogenous hormone levels in shoots developed on medium with low concentrations of NAA. The concentration of endogenous IAA was highest in the 20th generation shoots, which also exhibited the strongest rooting ability. However, the highest GA concentration was observed in the 40th generation shoots, which exhibited a poor rooting capacity. For shoots subcultured for 40 generations, incubation on rooting medium containing IAA caused an enhanced root number, shoot length and survival rate. This suggested that the effects of IAA on shoot and root formation were positive. PBZ promoted plantlet regeneration fromin vitrocultures but impaired shoot elongation at high levels. Furthermore, PBZ improved performance ofin vitrocultures after long-term (3 to 4 y) subculture. These results suggest the inhibitory role of a high endogenous GA level in plant regeneration and the use of appropriate levels of PBZ for plant regeneration ofP. massoniana.