Resource Allocation And Metallothionein Gene Expression Profiles Of Vicia Faba L. And Zea Mays L. Under Chronic Pollution Of Pb, Cd

Pollution can affect the plant morphological structure, physiological metabolism and eventually lead to the changes of plant resources configuration and differentiations of gene expression. Although they were reported times, but the changes of plant resource allocation and the differences of related genes expression under chronic pollution were still unclear. This study aimed to investigate plant resources configuration and metallothionein, under the threat of heavy metals.Three varieties of Vicia faba L.(in this paper, symbolised with A, B, C) and three varieties of Zea mays L. (in this paper, symbolised with Z1, Z2, Z3) were choosen as the research object. Different tissues and organs of the plants treated in different conditions of metal pollution in the fields were sampled and dry quality quantitative determination of calorific value were determined. qRT-PCR was used to detect the metallothionein expression quantity in the roots of Vicia faba L. and Zea mays L. varieties. My new findings are as follows:(1) Pb and Cd pollutions have certain impact on the biomass allocation in both Vicia faba L. and Zea mays L.The conditions of heavy metal pollutions resulted in reducing total biomass. Under the different conditions of different pollutions, plant biomass of different organs have different trends of changes. In order to adapt to the heavy metal pollutions plants of both species generally tend to reduce plant growth investment while increase the reproductive development and root growth.(2) Under the conditions of Pb, Cd pollutions, energy configurayions of Vicia faba L. and Zea mays L. were also affected. Under the condition of continuous pollution gross calorific are improved. A variety of Vicia faba L. root, pods and seeds of calorific value increased with the increase of concentration of pollution; B varieties under the Cd pollution stem, root and seeds after the calorific value of the lower first increases, when the concentration of Pb pollution and low each organ higher calorific value, high concentrations of each organ lower heating value; C varieties of beans is calorific value appear when in low concentration of heavy metal pollution is reduced, and the pollution levels, calorific value are rebounding. Total investment in the energy, with the increase of concentration of pollution, energy investment slightly higher, at the same time increased the root system of energy investment ratio in response to heavy metal pollution. Three varieties of Zea mays L. also showed similar to bean energy configuration, such as energy configuration to ensure the plant reproductive organs of energy input, at the same time increased the root of the energy input can be very good deal with the impact of heavy metal pollution on plants.(3) Continued pollution in Pb, Cd in the Vicia faba L. and Zea mays L. root system under the conditions of metallothionein in transcription level has increased. Under Cd pollution, and high dose of Pb pollution condition, the B variety of Vicia faba L. in the highest amount of metallothionein expression, while low doses of Pb pollution of Vicia faba L. varieties under C the highest amount of metallothionein expression. In Zea mays L. species, low doses of Cd pollution, Pb pollution has meet pollution cases, Z1 varieties, the highest amount of metallothionein expression in the second is the expression of Z2 varieties quantity is high, and Z3 varieties of metallothionein expression quantity is the lowest, in high concentration of Cd pollution cases, Zea mays L. Z3 varieties of metallothionein expression quantity is higher than Z2 varieties than Z1 varieties. Metallothionein as an indicator of heavy metal pollution response mechanism, the increased amount of it will be significant repression of toxic heavy metals.Discuss that metallothionein as heavy metal pollution response mechanism under the condition of plant resistance is one of the most important indicators, metallothionein as heavy metal pollution response mechanism under the condition of plant resistance is one of the most important indicators, the increased amount of it will be significant repression of toxic heavy metals. Two plant roots were increased the metallothionein expression increased to resist pollution, thus the root biomass, calorific value level are relatively stable or increased; Plant roots Energy configuration in preference to other tissues and organs under the heavy metal pollution, that ensure the plant for resource access level, and improve the whole plant adaptability under the condition of the pollution. But the mechanism and process need further research.