不同葡萄砧木品种需冷量及低温时长对芽休眠相关基因表达的影响

Effects of chilling requirement and chilling duration on the expression of bud dormancy-related genes in different grape rootstock varieties

  • 摘要: 【目的】探究不同葡萄砧木品种需冷量及低温时长对芽休眠相关基因表达的影响,为筛选热区葡萄低需冷量砧木品种及探究葡萄萌芽进程调控机制提供理论依据。【方法】以15个葡萄砧木品种的冬季修剪枝梢为试验材料,进行不同低温时长处理,处理温度为(4±1)℃,测定各砧木品种的需冷量,统计各葡萄砧木品种萌芽进程;并研究需冷量有差异的葡萄砧木品种,在低温处理打破休眠过程中枝梢中可溶性总糖和淀粉含量变化;通过实时荧光定量PCR检测砧木芽中休眠相关基因的相对表达量。【结果】贝达、SO4、101-14、110R、188-08、3309C、140R、Valliant、山河2号、BR No. 2、Fercal和5C等12个品种需冷量为0 h,1103P需冷量为168 h。1103P砧木枝梢中可溶性总糖含量随着低温处理时长增加呈显著增加趋势(P<0.05,下同);在低温处理304 h时,可溶性总糖含量最高,达2.55 μg/g,此时枝梢中淀粉含量显著降低,仅0.06 μg/g,低需冷量的3309C枝梢中淀粉含量在3个低温时长处理间无显著差异(P>0.05,下同)。1103P砧木随着低温处理时长增加,胼胝体合成酶基因VvCALLOSE SYNTHASE1的相对表达量呈显著下降趋势,未低温处理的1103P冬芽中VvCALLOSE SYNTHASE1基因的相对表达量显著高于3309C。3个低温时长处理中,1103P芽中β-1,3-葡聚糖酶基因VvGLU1、ABA合成关键酶基因VvNCED1、GA20-氧化酶基因VvGA20ox-2、响应低温胁迫的重要转录因子基因VvbHLH92和开花抑制基因VvSVP的相对表达量在低温处理304 h时最高。未进入内休眠的3309C在低温处理过程中,VvCALLOSE SYNTHASE1VvSVP基因的相对表达量无显著变化,未经低温处理时的3309C芽中VvGLU1基因、ABA合成诱导因子基因VvXERICOVvbHLH92基因的相对表达量最高。3个低温时长下1103P芽中VvSVP基因的相对表达量均显著高于3309C。【结论】筛选出贝达、SO4、101-14、110R、188-08、3309C、140R、Valliant、山河2号、BR No. 2、Fercal和5C等12个不需经低温处理即可萌芽的砧木品种,葡萄的萌芽受品种需冷量、营养和休眠相关基因的共同调控。

     

    Abstract: 【Objective】This study aimed to investigate the effects of chilling requirement and chilling duration on the expression of bud dormancy-related genes in different grape rootstock varieties,providing theoretical basis for screening low-chilling rootstock varieties suitable for tropical and subtropical regions and exploring the regulatory mechanisms of grape germination.【Method】Winter pruning bud-wood of 15 grape rootstock varieties were used as test materials,and subjected to different chilling duration treatments at(4±1)℃. The chilling requirement of each grape rootstock variety was detected,and the germination process was recorded. The changes of total soluble sugar and starch content in branches with different chilling requirements were analyzed during dormancy release induced by chilling requirement. The relative expression levels of dormancy-related genes in the buds were determined using real-time fluorescence quantitative PCR. 【Result】The chilling requirement of 12 grape varieties including Bayda,SO4,101-14,110R,188-08,3309C,140R, Valliant,Shanhe No. 2,BR No. 2,Fercal and 5C was 0 h,while the chilling requirement of 1103P was 168 h. The total soluble sugar content in the branches of 1103P rootstocks increased significantly with chilling duration added(P<0.05, the same below),reaching a maximum of 2.55 μg/g at 304 h of chilling duration,and the starch content in branches decreased significantly to 0.06 μg/g. In contrast,there was no significant difference in starch content in branches of 3309 C with low chilling requirement among the three chilling duration treatments(P0.05,the same below). With increasing chillinng duration treatment,the relative expression of VvCALLOSE SYNTHASE1 in 1103P decreased significantly. The relative expression of callosal synthase gene VvCALLOSE SYNTHASE1 in 1103P winter buds without chilling treatment was significantly higher than that in 3309C. Among the three chilling duration treatments,the relative expression levels of β -1, 3-glucanase gene VvGLU1,ABA synthesis key enzyme gene VvNCED1,GA20-oxidase gene VvGA20ox-2,key transcription factor gene responding to cold stress VvbHLH92 and flowering inhibitory gene VvSVP in 1103P buds were the highest at 304 h of chilling treatment. In 3309C which did not enter endodormancy,the relative expression levels of VvCALLOSE SYNTHASE1 and VvSVP genes did not change significantly. The relative expression levels of VvGLU1 gene,ABA biosynthesis inducer VvXERICO gene and VvbHLH92 in 3309C buds were the highest without chilling treatment. The relative expression of VvSVP gene in 1103P buds was significantly higher than that in 3309C under all three chilling duration treatments.【Conclusion】The twelve grape rootstock varieties,including Bayda,SO4,101-14, 110R,188-08,3309C,140R,Valliant,Shanhe No. 2,BR No. 2,Fercal and 5C,are identified as rootstock varieties not requiring chilling requirement for germination. Grape germination is co-regulated by chilling requirement,nutrients and dormancy-related genes.

     

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