Selection Of Reference Renes In Creeping Bentgrass And Studies On The Mechanism Of Improving The Seashore Paspalun's Salt Tolerance By Addition Of Sulfur

(A)Selection of reference genes in creeping bentgrassExamination of gene expression using quantitative real-time PCR(qRT-PCR)in plant responses to abiotic stresses can provide valuable information for stress-tolerance improvement.Selecting stable reference genes for qRT-PCR analysis is critically important.The objective of this study was to determine the stability of expression for eight candidate reference genes(ACT,EF1a,TUB,UPL7,GAPDH,PP2A,PEPKR1 and CACS)in two tissues(roots and leaves)of a perennial grass species under four abiotic stresses(salt,drought,cold,and heat)using four programs(GeNorm,NormFinder,BestKeeper,and RefFinder).At the same time,the qRT-PCR analysis of a target gene,ASAP expression patterns in response to salinity and drought stress,confirmed the reliability of those selected and stable reference genes.Identification of stable reference genes in creeping bentgrass will improve assay accuracy for selecting stress-tolerance genes and identifying molecular mechanisms conferring stress tolerance in this species.The results showed that:1.The combinations of CACS and UPL7 or PP2A and ACT were stably expressed in salt-treated roots or leaves;2.The combinations of GAPDH and CACS or PP2A and PEPKR1 were stable in roots and leaves under drought stress;3.CACS and PP2A exhibited stable expression in cold-treated roots and the combination of EF1a and UPL7 was also stable in cold-treated leaves;4.CACS and PP2A were the two most stable reference genes in heat-stressed roots and UPL7 combined with GAPDH and PP2A was stably expressed in heat-stressed leaves.(B)Studies on the mechanism of improving the seashore paspalun's salt tolerance by addition of sulfurNowadays,the widespread soil problems of Salinization and the secondary salinization have become a global problem in the world.Among more than 500 million acres of saline-alkali soil in our country,about 100 million acres have already been reclaimed.For the salt stress,which limits the utilization of saline land seriously,affects the growth and yield of the plant.To solve the problem mentioned above,the government has taken a number of measures to improve the utilization of the soil.But they all have defects,such as large projects,the high cost and poor sustainability.Whereas,the way of select salt-tolerant plant and scientific management measures(exogenous substances applied to improve plant salt tolerance)is the most and effective ways.Sulfur nutrition is essential for plant growth,plays an irreplaceable role when the plant against abiotic stress(such as salt stress).The mitigation of salt stress by the addition of sulfur within paspalum was studied,based on the "2000" Seashore Paspalum.The results obtained presently are as follow.1.The addition of sulfur can effectively improve the net photosynthesis of plants,the conversion efficiency of distance light,content of chlorophyll,transpiration rate and stomatal conductance.of Seashore Paspalum under salt stress.2.The addition of sulfur can effectively alleviate the damage of the cell membrane of Seashore Paspalum under salt stress,and it also can reduce the content of MDA.