Physiological Effects Of Grafting On Eggplant Seedlings Under Low Temperature Stress And Low Temperature Tolerance Gene Mining Based On Transcriptome Sequencing

Eggplant is a kind of solanaceae plant that originated in tropical Asia.At present,China has become the producer with the largest planting area and the highest yield of eggplant.Eggplant occupies an important position in the national consumption of our country.However,low temperature stress has become an important factor restricting the production of greenhouse vegetables in autumn and winter.At present,in addition to cultivating low-temperature-tolerant vegetable varieties,the strategy to solve this problem can also quickly improve the low-temperature stress tolerance of the aboveground parts of vegetables by grafting rootstocks with strong cold-tolerance in a short period of time.Therefore,grafting technology has become one of the important methods to solve the poor disease resistance and stress resistance of vegetable varieties in production,but there is little research in eggplant.In order to explore how grafting can solve the problem of low temperature stress tolerance of eggplants,this study used the close-source wild species of ’Solanum aculeatissimum Jacq’ with strong low temperature stress tolerance as the rootstock,and the cultivated species of’He Bao eggplant’ as the scion for grafting,and treated the low temperature stress.A series of physiological indexes in the leaves of the lower scion were measured.In addition,in order to further understand the molecular mechanism related to the eggplant root system,we conducted a transcriptome analysis of the eggplant root system.The experimental results are as follows:1.The results showed that the content of chlorophyll,CAT and soluble sugar were significantly higher than that of self rooted He Bao eggplant in the same low temperature environment,while the content of MDA was lower,which indicated that the grafted Solanum aculeatissimum Jacq had stronger ability to resist the damage caused by low temperature environment,delayed the time of plant death,and effectively improved the ability of low temperature stress tolerance at seedling stage,the results also showed that the root system of Solanum aculeatissimum Jacq may improve the tolerance to low temperature stress.2.Grafting itself had little effect on the physiological indexes of Eggplant Seedlings under low temperature stress,and could not change the ability of low temperature stress tolerance of eggplant,but cold tolerant eggplant could obtain cold tolerance by grafting cold tolerant materials 3.545 differently expressed genes in response to low temperature stress were identified from the grafting materials of purpurea,of which 241 were up-regulated and 304 were down-regulated.167 differently expressed genes in response to low temperature stress were identified in the materials of He Bao eggplant grafted with Solanum aculeatissimum Jacq,65 of which were up-regulated and 102 were down-regulated.Six genes with significant differential expression between the two were screened out,and six genes were specifically up-regulated in the materials of the He Bao eggplant grafted with Solanum aculeatissimum Jacq.It is speculated that the expression of these genes may regulate the ability of eggplant seedlings to withstand low temperature stress.