Cloning And Functional Preliminary Verification Of Sweetpotato Potassium Transporter IbHKT-like Gene

In the process of plant growth and development,maintaining the dynamic balance of potassium plays a pivotal role in high yield of crops.Potassium does not participate in the composition of organic matters in plants,but it plays an important role in physiological and biochemical processes such as plant morphology,cell infiltration regulation and organelle maintenance.Sweetpotato[Ipomoea batatas(L.)Lam.] is a typical "potassium-loving" crop,and right amount of potassium have a profound effect on the yield and quality of sweetpotato.However,the current situation that famine of soil potassium deficiency and lack of potassium fertilizer resources in China has seriously restricted production of agriculture and yield and quality of crop.Therefore,it is necessary to improve the absorption and utilization efficiency of potassium in plants to alleviate the current situation of potassium deficiency in China.In the study,a high affinity potassium transporter Ib HKT-like from sweetpotato was cloned and its function was verified.The main results of this paper are as follows:1.Bioinformatics analysis and subcellular localization showed that the potassium transporter Ib HKT-like protein in sweetpotato had two Trk H conservative domains and ten transmembrane fragments.The amino acid sequence of Ib HKT-like protein was very similar to that of In HKT6 of Convolvulaceae.Ib HKT-like protein was mainly located on the cytoplasmic membrane.2.Analysis of expression pattern showed that Ib HKT-like gene was most expressed in leaves.The Ib HKT-like gene was induced to express by potassium deficiency,cold,drought,high salt and hydrogen peroxide.3.In order to clarify the function of Ib HKT-like gene,we constructed an overexpression vector p CAMBIA0390 with a Ds Red marker,and infected Xuzishu 8 seedling through genetic transformation mediated by Agrobacterium rhizogenes strain K599 and successfully obtained a sweetpotato root plant overexpressing Ib HKT-like.4.Phenotypic analysis and transmission electron microscopic observation of root tips of sweetpotato overexpressing Ib HKT-like showed that sweetpotato overexpressing Ib HKT-like gene could protect cell structure,maintain the integrity of mitochondria,endoplasmic reticulum and golgi apparatus.5.Root tip potassium current and total potassium of sweetpotato overexpressing Ib HKT-like were measured.The results showed that the internal potassium current of sweet potato overexpressing Ib HKT-like was increased and the total potassium content was increased under low potassium condition.