Study Of Transgenic Tomato Expressing Human Metallothionein Gene On Zinc Tolerance

Metallothionein (Metallothionein, MT) is produced by plants, animals and micro-organisms for a class of low molecular weight, rich in cysteine residues, with metal binding capacity of peptides. What is more, it has a variety of biological functions, related to biological organisms growth and development various stages. In recent years, MT due to its unique physiological functions, making it has been involved in research and application in many areas of agriculture, environment, bio-engineering, medicine, health care, etc., which use a lot of heavy metal accumulation characteristics MT has become a focus of attention. Zinc (zinc), as a kind of essential trace elements participate in many organisms, enzymatic reaction process is one of the important nutrients to maintain life, but when its excessive creates the toxicity of heavy metals. MT can reduce the toxicity of heavy metals chelated Zn and improve resistance of plants to heavy metal zinc, it is of great significance in terms of lifting heavy metal zinc poison.In this study, a constitutive promoter CaMV 35S regulatory HsMTIL human metallothionein gene expression in tomato plants and research the transgenic tomato plants to heavy metal tolerance of Zn2+. For the future, expect to obtain zinc-rich or super-rich tomato Zn2+make a new material foundation.The main results were as follows:1 The construction of expression vector pVCT2269 which contain gene 35S-Ω::HsMT1L.Through the carrier pVCT2259 and pCAMBIA1301 were digested fragment was recovered, after overnight connection products were transformed Escherichia coli cells. Finally get vector pVCT2269 containing the 35S-Ω::HsMT1L gene.2 Obtained transgenic tomato plants containing 35S-Ω::HsMT1L geneThe binary vectors with 35S-Ω::HsMT1L gene were transformed into Agrobacterium tumefacious strain LBA4404 by the freeze-thaw method and obtained the transgenic tomato plants.3 Transferred 35S-Ω::HsMT1L gene can improve tomato the Zn2+ toleranceObserving plant height, leaf, root and other phenotypic changes of wild-type and transgenic tomato by 1.2 mmol/L ZnSCO4 treated, indicating the tomato transferred 35S-Ω::HsMT1L gene can improved the heavy metal Zn2+ tolerance. Under ZnSO4 treatment, the overground parts and roots of tomato plants Zn2+ content both were increased significantly compared with the control, but genetically modified tomatoes overground parts and roots Zn2+ content increase 9.5% and 28.7% higher than the wild type, respectively. The roots Zn2+ concentration of Transgenic tomato C and J lines are difference compared with the wild type reached a very significant and significant level.Show that the roots of transgenic plants have obvious enrichment of Zn2+.