超表达马尾松PmPT3基因提高拟南芥耐低磷能力

Overexpression of Pinus massoniana PmPT3 Gene in Arabidopsis thaliana Increasing Low Phosphorus Tolerance

旨在探讨马尾松PmPT3基因在低磷胁迫条件下对拟南芥磷吸收利用的影响,实现林木优良基因的利用。通过构建马尾松PmPT3基因超表达载体pBWA(V)HS-PmPT3,采用花序浸染法遗传转化拟南芥。经筛选和检测,共获得4株T3代纯合株系;磷处理结果表明:超表达马尾松PmPT3基因显著提高了转基因拟南芥超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)的活性,分别是野生型植株的2.17倍、1.59倍、1.81倍;丙二醛(MDA)含量较野生型植株降低了47.58%。转基因拟南芥的地上部分和根部总磷含量及无机磷含量较野生型相比,分别提高了1.26倍和1.74倍及1.38倍和1.89倍。转基因植株较野生型地上部干重提高了45.46%,根干重提高了55.56%,总干重提高了46.15%。与正常供磷条件相比,处于低磷胁迫下的拟南芥转基因植株,其根部和地上部分中的PmPT3基因表达量显著上调,且在根部达到极显著水平。结果表明,超表达马尾松PmPT3基因可以提高低磷胁迫下拟南芥中保护酶活性、降低丙二醛产生,促进拟南芥对磷元素的吸收,从而提高拟南芥耐低磷胁迫的能力,为通过基因工程创制耐低磷新种质提供了科学依据。

The aim of this study is to explore the effect of PmPT3 gene of Pinus massoniana on phosphorus uptake and utilization in Arabidopsis thaliana under low-phosphorus stress,and to achieve the utilization of excellent genes in trees.The PmPT3 gene overexpression vector pBWA(V)HS-PmPT3 was constructed and transformed into A.thaliana by inflorescence infection method.Four homozygous strains of T3 generation were obtained by screening and detection.The results of phosphorus treatment showed that overexpression of the PmPT3 gene of P.massoniana significantly increased the activities of superoxide dismutase(SOD),peroxidase(POD)and catalase(CAT)in transgenic Arabidopsis,respectively,it was 2.17 times,1.59 times,and 1.81 times of the wild-type plant.It reduced malondialdehyde(MDA)content,47.58%lower than that of wild-type plants.Compared with the wild-type,the total phosphorus content and inorganic phosphorus content of the aerial parts and roots of transgenic Arabidopsis increased by 1.26 times and 1.74 times,as well as 1.38 times and 1.89 times,respectively.Compared with the wild type,the dry weight of the transgenic plant shoots increased by 45.46%,the dry weight of roots by 55.56%,and the total dry weight by 46.15%.Compared with normal phosphorus supply conditions,the expressions of PmPT3 gene in the root and shoot parts of transgenic A.thaliana under low phosphorus stress was significantly up-regulated,and reached a very significant level in the roots.These results indicated that the overexpression of PmPT3 gene from P.massoniana increased the activities of protective enzymes,reduced the production of MDA,and promoted the absorption of phosphorus in Arabidopsis under low phosphorus stress.Therefore,overexpression of the PmPT3 gene improved the ability of Arabidopsis to tolerate low phosphorus stress.This work may provide a reliable scientific basis for the creation of new low phosphorus tolerant germplasm through genetic engineering.