Chilling and gibberellin acids hyperinduce β-1,3-glucanases to reopen transport corridor and break endodormancy in tree peony (Paeonia suffruticosa)
Chilling and gibberellin acids hyperinduce β-1,3-glucanases to reopen transport corridor and break endodormancy in tree peony (Paeonia suffruticosa)
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DOI：
10.1016/j.plaphy.2021.09.002
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发表时间：
2021-09-13
影响因子：
6.5
通讯作者：
Gai, Shupeng
中科院分区：
文献类型：
--
作者：
Gao, Xuekai;Yuan, Yanchao;Gai, Shupeng
芽内休眠伴随着胼胝质沉积导致的运输通道孔堵塞，其恢复生长需要调用β -1,3-葡聚糖酶（BGs）来疏通管道。为了了解其工作方式，研究了赤霉素酸诱导牡丹休眠释放过程中转运通道的状态，并鉴定了候选BGs。钙黄蛋白反映胞间连丝的通透性，低温第0 d芽内未见钙黄蛋白，茎韧皮部周围有密度苯胺蓝荧光。随着低温积累的增加，芽中葡聚糖含量逐渐下降，gulcanase活性逐渐升高，冷芽21 d时钙黄蛋白达到花原基顶部。GA(3)和GA(4)均能促进芽的萌发和生长，并能迅速疏通运输通道，其中GA(3)效果更好。结合转录谱分析和定量PCR分析，检测到多个候选β -1,3-葡聚糖酶基因。PsBG1、PsBG3、PsBG6、PsBG8和PsBG9经冷积累诱导，原核表达后呈现层粘连蛋白水解活性，而PsBG1、PsBG3、PsBG8和PsBG9对GAs有响应。亚细胞定位显示PsBG6和PsBG9为胞间连丝居民。综上所述，PsBG6在低温积累响应中起重要作用，PsBG9在气体诱导休眠释放中起核心作用，它们可以作为牡丹休眠释放的标记基因。这些结果对了解牡丹休眠调控机制具有重要价值，并为牡丹催育技术的研究提供了重要依据。
Bud endodormancy is accompanied by transport channel apertures blockage through callose deposition, and its resume to growth requires evoking beta-1,3-glucanases (BGs) to unchoke the conduit. To understand out its working manner, the statuses of the transport channels were evaluated and candidate BGs were identified during chilling and gibberellin acids (GA) induced dormancy release in tree peony. Calcein reflects plasmodesmata permeability, and no calcein was observed in the bud together with density aniline blue fluorescent around the stem phloem at 0 d chilling. With the increase of chilling accumulation, the contents of glucan declined and the activities of gulcanase increased gradually in buds, and the calcein reached the top of flower primordia at 21 d chilled bud. Both GA(3) and GA(4) feedings promoted bud sprouting and growth along with rapidly unchoking the transport channels, and GA(3) was more effective. Several candidate beta-1,3-glucanase genes were detected, combining transcriptional profiling and quantitative PCR analysis. PsBG1, PsBG3, PsBG6, PsBG8 and PsBG9 were inducible by chilling accumulation and presented laminarin hydrolyzing activities after prokaryotically expression, while PsBG1, PsBG3, PsBG8 and PsBG9 responded to GAs application. Subcellular localizations revealed that PsBG6 and PsBG9 were plasmodesmata residents. It was concluded that PsBG6 played a vital role in chilling accumulation response and PsBG9 was central in GAs-induced dormancy release, and they could be used as marker genes for dormancy release in tree peony. These results were of great value to understand the mechanism of dormancy regulation and as an important fundamental for forcing culture technology in tree peony.