Influence Of Arsenic Stress On Physiological And Biochemical Characteristics Of Different Cultivars Of Maize (Zea Mays L.)

Arsenic (As) is one of the major elements involved in heavy metal pollution, the toxicity of the As is strong, not only will cause serious soil pollution led to the decrease of the yield and quality of agricultural products, but also even absorbed by plants accumulate and eventually be absorbed by human body through food chain migration harm to health. Currently on the As distribution in soil and its influencing factor process research has the certain reports, but about the As and the relationship between plants and their influence on plant physiological and biochemical effect mechanism is also few studies.In liaoning province in this paper, therefore, one of the main crops of corn were used As material, by choosing to clear difference As accumulation of three groups of maize varieties, each group choose two typical.By hydroponic experiment under the As stress the impact on maize growth and development, physical and chemical properties and comparison and discussion on ultrastructure, explore the As accumulated in different maize varieties in vivo distribution regularity and the physical and chemical reaction and the relations between ultrastructure change of for accumulating maize varieties resistance As low As study provide theoretical basis for the mechanism of poisoning, the results are As follows:1. The influence of As on the ultrastructure of different cultivars of maizeMaize mesophyll cells As poisons ultrastructure showed different changes.As high accumulation of cell wall thickening and serious plasmolysis, As low accumulation of varieties of cell wall thickening and plasmolysis phenomenon was not significant;As low accumulation fuzzy varieties of cell membrane invagination, dissolve As serious high accumulation of variety cell membrane invagination;As high accumulation of varieties chloroplasts broken melting dispersion capsule rupture, sparse matrix, grana lamella and grana thylakoid dissolve scattered disorderly membranous structure fracture, the As low fuzzy accumulation varieties cell chloroplast swelling capsule, grana lamella and grana thylakoid arrangement disorder;As low accumulation varieties swollen mitochondria membrane structure are fuzzy, the As high accumulation of varieties swollen mitochondria and vacuoles, capsule is broken;As high accumulation and low accumulation varieties nuclei deformation nucleoli are split into many small nucleoli, condensed chromatin cavitation, As high accumulation of varieties of membrane structure fuzzy dissolved phenomenon more significantly than As low accumulation varieties;As high accumulation of endoplasmic reticulum disappeared, and As low variety endoplasmic reticulum swelling fuzzy accumulation.2. The absorption, distribution and accumulation of As of the different cultivars of maize under AsCorn on the absorption of the As performance for underground part> part on the ground, As environment As high accumulation of variety roots and strong ability to accumulate in the body and As part of the strong ability to transport to the ground, As low environment variety roots As accumulation and weak ability to accumulate in the body and As part of the transport capacity is weak to the ground, and accumulation of the As level medium variety environment As a kind of roots and As part of the transfer to the ground between both the As high accumulation and low accumulation between varieties, the strong ability of environment As a roots but As part of the transport capacity is weak to the ground.Besides absorbing ability of environment As corn, As to the ground part of the transport ability of corn in the corn part accumulation As play vital role on the ground.3. The growth of different varieties of different cultivars of maize under AsLow concentration of the As for different varieties of maize seed germination, high concentrations of the As there was a significant inhibitory effect on maize seed germination, no obvious differences between varieties.Low concentration of the As of corn varieties As low accumulation of plant height, root length, root cap ratio and dry matter weight has a promoting effect, varieties of the As high accumulation promoting effect was not significant; A high concentration of the As to its inhibitory effect.As accumulation capacity of different varieties of maize growth show that the difference between varieties, the influence of the As low accumulation of varieties of corn shows better growth form.4. The resitance of growth of different cultivars of maize under AsWith the increase of the As concentration of corn leaf and root plasma membrane permeability increase, significant differences between varieties, the As high accumulation of varieties of corn greater concentration range lower leaves and root plasma membrane permeability.Leaf proline content and root of the As stress response after all increased with the increase of the concentration to reduce, there are obvious differences between varieties, the As low accumulation of varieties of corn bigger concentration range of higher proline content,20 to 40 mg/L As beyond the resistance of corn to adjust ability.Soluble protein content of maize leaves and roots of the As stress response are reduced with the increase of the concentration of, As the lower accumulation ability of maize varieties leaves and root system to maintain body soluble protein synthesis and the stronger ability to resist soluble protein consumption.Corn leaf soluble sugar content reduced with the increase of the As concentration increases after the first, soluble sugar content and root decreased with increasing the concentration of the As, varieties and remarkable differences, As low accumulation varieties can retain a greater possibility of synthesis and content of soluble sugar in plant.MDA content of maize leaves and roots increased with the increase of the concentration of the As, varieties and remarkable differences, As fewer varieties of low accumulation of MDA accumulation showed a lower level As stress damage.As stress significantly increased the content of maize leaves and roots of the NPT, varieties and remarkable differences, As low accumulation varieties more keep the contents of the NPT, show better in science.5. The antioxidant enzyme activity of different cultivars of maize under AsAs added As the increase of concentration, corn leaf and root of SOD and POD activity were lower after increased first, corn leaf reduced after the CAT activity increased first, CAT activity in high concentrations with the decreasing concentration increasing, there are significant differences between varieties, the As low accumulation varieties have maintained high oxidase activity, more show better defences As stress.Taken together, different varieties of maize under the stress of the As, physiological and biochemical responses in cell ultrastructure and have significant difference.As high accumulation of maize varieties ultrastructure damage more serious, physiological and biochemical reaction reflects the relatively less As low accumulation of maize varieties As resistance and detoxification ability under the As stress.