蔗糖添加对杉木低磷胁迫响应和蔗糖代谢的影响

Effects of sucrose addition on response of Chinese fir to low phosphorus stress and sucrose metabolism

为了揭示低磷胁迫下蔗糖对杉木低磷胁迫响应和蔗糖代谢的影响,选用两种不同磷效率杉木家系M32和M28进行低磷胁迫下的蔗糖添加试验,分析蔗糖添加对低磷胁迫下杉木形态特征、生理特性和低磷诱导相关基因表达的影响。结果表明:蔗糖添加促进了低磷胁迫下杉木苗高、根长、根表面积、根平均直径、根体积、根叶组织蔗糖含量和根叶组织无机磷含量的增加,但仍明显低于正常供磷处理下添加蔗糖处理的杉木增量。低磷促进杉木叶中花青素的积累,而正常供磷和低磷胁迫下的蔗糖添加处理都显著促进了叶片花青素含量的增加。随着胁迫时间的延长,M28与M32在根、叶组织的蔗糖含量存在显著差异,且M28根叶组织中的蔗糖合成酶活性和蔗糖磷酸合成酶活性都高于M32。蔗糖合成酶ClSuSy在M28和M32根系中受低磷胁迫诱导下调表达,但蔗糖添加处理明显诱导ClSuSy表达量升高,M28在正常供磷并添加蔗糖处理下的ClSuSy表达量显著高于其它处理。蔗糖转运蛋白SUT4、磷转运蛋白ClPht1;4、紫色酸性磷酸酶PAP1和PAP11在M28和M32根系中总体上受低磷胁迫诱导上调表达,且受蔗糖添加处理诱导下调表达。低磷胁迫下,添加或不添加蔗糖处理的M32根系SUT4的表达量均在15d时显著升高,并在45d时回落到正常水平。ClPht1;4和PAP1在低磷胁迫15d的表达量显著高于45d时的表达量,且ClPht1;4在M32根系中的表达量远高于M28。本研究表明,蔗糖对杉木低磷胁迫响应和糖代谢有重要的影响作用,低磷胁迫下添加蔗糖处理能够在一定程度上缓解杉木低磷胁迫响应。

In order to reveal the effect of sucrose on the response to phosphorus starvation stress and sucrose metabolism of Chinese fir under low phosphorus stress,two Chinese fir(Cunninghamialanceolata)genotypes M32 and M28 with different phosphorus efficiency were selected for the sucrose addition experiment under low phosphorus stress,and theeffects of sucrose addition on morphological and physiological characteristics of the Chinese fir under low phosphorus stress and gene expression related to low phosphorus induction were analyzed.The results showed that the addition of sucrose promoted the increase of Chinese fir seedling height,root length,root surface area,average root diameter,root volume,root and leaf tissue sucrose content,and root and leaf tissue inorganic phosphorus content under low phosphorus stress,but it was still significantly lower than the normal phosphorus supply.Phosphorus starvation promoted the accumulation of anthocyanin in Chinese fir leaves,while the addition of sucrose under normal phosphorus supply and low phosphorus stress significantly promoted the increase of anthocyanin content in leaves.With the prolongation of stress time,the sucrose content in root and leaf tissue of M28 and M32 are significantly different,and the sucrose synthase activity and sucrose phosphate synthase activity in root and leaf tissue of M28 are higher than those of M32.The expression of sucrose synthase ClSuSy in the root of M28 and M32 was down-regulated by low phosphorus stress,but the addition of sucrose significantly increased the expression of ClSuSy.The expression of ClSuSy of M28 under the treatment of normal phosphorus supply and addition of sucrose was significantly higher than that of other treatments.Sucrose transporter SUT4,phosphorus transporter ClPht1;4,purple acid phosphatase PAP1 and PAP11 were generally up-regulated by low phosphorus stress in roots of M28 and M32,and down-regulated by sucrose addition treatment.Under phosphorus starvationstress,the expression level of SUT4 in M32 roots treated with or without sucrose increased significantly at 15 days,and fell to normal levels at 45 days.The expression levels of ClPht1;4 and PAP1 under low phosphorus stress at 15 days were significantly higher than those at 45 days,and the expression of ClPht1;4 in roots of M32 was much higher than that of M28.This study shows that sucrose has an important effect on the response of Chinese fir to low phosphorus stress and sucrose metabolism.The addition of sucrose treatment under low phosphorus stress can alleviate the response of Chinese fir to low phosphorus stress to a certain extent.