Comparative Study Of The Photosynthate Allocation In Chorispora Bungeana And Arabidopsis Thaliana

Photosynthetic products are the material basis of plant cell activity.The distribution of photosynthetic products in different cells,tissues and organs have direct effects on the growth,development and environmental adaptability of plants.Under low temperature,the material cost of plants to deal with stress must have an influence on the distribution of plant photosynthetic products,and then on the plant growth and development and resistance.Therefore,the study on the distribution of photosynthetic products under low temperature is very important to elucidate the mechanism of low temperature adaptation of plants,but there is a lack of relevant researches at present.This paper researches on the photosynthetic product in leaves(leaf)A new and mature leaves(leaf)B and old leaves(leaf)C distribution rule and the influence of cold acclimation using Chorispora bungeana and Arabidopsis as materials,to discuss the resistance mechanism of strong natural antifreeze plant.This article main results were as follows:1.With the analysis of the total carbon content of Chorispora bungeana and Arabidopsis at normal and low temperature,we found the total carbon all showed A > B > C in two plants.Relatively more photosynthesis products could get in young leaves.Cold acclimation reduced the total carbon in C leaf position of Chorispora bungeana and had no obvious differences in Arabidopsis.2.To further investigate whether cold acclimation had an effect on the nonstructural carbohydrates of two plants,we analysed the contents of nonstructural carbohydrates in different leaf positions of Chorispora bungeana and Arabidopsis at normal and low temperatures.There was a decrease tendency in the soluble sugar content from A to B to C under normal and low temperatures in Chorispora bungeana,it denoted that there is more soluble sugar in young leaves.While it is opposite in sucrose and fructose contents in Chorispora bungeana.Cold acclimation increased the soluble sugar and sucrose and fructose contents in A?B?C leaf positions of Chorispora bungeana.As Arabidopsis,the trend of each leaf position in the soluble sugar content was A>B and C at 8:00,there is no difference at 20:00.And there are no differences both of sucrose and fructose contents at 8:00 and 20:00.Cold acclimation increased the soluble sugar and sucrose and fructose contents in A?B?C leaf positions of Arabidopsis.The result appeared that A>B>C in starch contents in both two plants in normal and low temperature.Cold acclimation increased the starch contents in A?B?C leaf positions of Chorispora bungeana and reduced the starch contents of Arabidopsis.3.Studies on structural carbohydrates of two plants showed that there is an increase tendency in pectin content from A to B to C in Chorispora bungeana both in normal and low temperature,that is,there are more pectin in old leaves.However the largest pectin content was in B in Arabidopsis.Cold acclimation decreased the pectin content in A?B?C leaf positions of Chorispora bungeana and increased the pectin content of Arabidopsis.As Chorispora bungeana,the lowest hemicellulose content was in A at normal temperature and there are no differences under low temperature.However,the hemicellulose content appeared that B>C>A in Arabidopsis.The largest cellulose content was in C in Chorispora bungeana and was in B in Arabidopsis.Cold acclimation increased the hemicellulose content in three leaf positions of Chorispora bungeana and had no differences in Arabidopsis.Also,cold acclimation increased the cellulose content in three leaf positions of Chorispora bungeana and Arabidopsis.These results showed that cold acclimation could affect the contents of structural carbohydrates in each leaf position of the two plants.4.The analysis of sucrose metabolism related enzyme specific activity showed that there was a tendency of A>B>C of SPS specific activity in Chorispora bungeana and Arabidopsis.It appeared that the tendency of A>B>C both of the neutral invertase and acid invertase specific activity in two plants under normal and low temperature.There was no difference in SPS specific activity in A,B,C leaf positions of the Chorispora bungeana and Arabidopsis under normal and low temperature after cold acclimation.And cold acclimation increased the neutral invertase specific activity in three leaf positions of two plants.The acid invertase specific activity in Chorispora bungeana three leaf positions all increased after cold acclimation,while decreased the acid invertase specific activity in A of Arabidopsis.5.Analyzing the expression of carbon assimilation transportation related genes including NVE1,NVE2,SWEET11,SWEET12 and SUT2 after cold acclimation.We found that there were no differences in the expression of NVE1 and NVE2 and INVE in Chorispora bungeana under normal temperature,and the expression of NVE2 and INVE also had no obvious differences under low temperature.In Arabidopsis,the expression of NVE1 and INVE was the lowest in leaf position B at normal temperature,and the NVE2 is lowest in leaf position A.Under low temperature,the expression of NVE1 was the lowest in leaf position B,the NVE2 and INVE is lowest in leaf position A.Cold acclimation increased NVE1?NVE2?INVE in three leaf positions of Chorispora bungeana.As Arabidops,the expression of NVE1 increased in three leaf positions after cold acclimation.The expression of NVE2 increased in A leaf position only and cold acclimation decreased the expression of INVE obviously.In Chorispora bungeana,under normal temperature,the expression of SWEET11 was the highest in C leaf position,and SWEET12 is the lowest in A leaf position,and SUT2 is the lowest in B leaf position.Under low temperature,the expression of SWEET11 in B leaf was the highest and SWEET12 in B leaf position was the lowest,and the trend of SUT2 expression was A > B > C.As Arabidopsis,the expression SWEET11 was the lowest in A leaf position and SWEET12 and SUT2 was the lowest in B leaf position.Cold acclimation increased the expression of SWEET12 and SUT2 in Chorispora bungeana.In Arabidopsis,there were no significant differences of the SWEET11,the expression of SWEET12 increased in A and B and SUT2 increased in B and C after cold acclimationThrough the Chorispora bungeana and Arabidopsis comparative study of different leaf photosynthetic product distribution,the paper concludes that not only low temperature can affect plants photosynthesis production distribution,but the Chorispora bungeana significantly differs from that of Arabidopsis photosynthesis product distribution characteristics and the response rules.The study's results laid foundation for the further investigation on the resistance mechanism of strong natural antifreeze plants,also provided theoretical basis and research direction for the future further exploring crop photosynthesis product distribution under low temperature stress,the breeding of new varieties,and then it has great practical significance to promote the development of agriculture.