Genome-wide Analysis Of PIN Genes And Stress Resistance-related Genes’ Screening And Identification Of In Tomato

Tomatoes originated from South America Peru,Ecuador,Bolivia etc.In sixteenth century,it began to do ornamental cultivation.Since early 1920 s,it began to growed in China as vegetable cultivation and it has become a major vegetable in China in the twentieth century.Tomatoes have many advantages,such as variety of cultivation,bright color of fruit,rich nutrition and high yield.However,it is easily affected by adverse conditions,resulting in a decline in quality and yield in the process of growth and development.In the season of insufficient vegetable supply,tomatoes are often affected by soil salinization,floods and droughts,which seriously restrict the supply and production of tomatoes.Auxin is one of the most important plant hormones that plays an important role throughout the life cycle from first to last of plants,including the formation of stems and floral meristems,the embryonic growth,apical dominance,gravitropism and response to internal and external stimuli.Therefore,auxin polar transport,auxin signal transduction and the relationship of auxin with abiotic stress have aroused people’s interest.Previous studies have shown that auxin is involved in almost aspects of plant growth and development.Polar transport of auxin is controlled by polar localization of auxin transport protein on the membrane,and the PIN protein family is a recognized auxin efflux carrier.In conclusion,a series of environmental stress responses can lead to polarization in specific domains and redirect the direction of auxin,including downstream regulation of subcellular transport of PINs protein.However,the mechanism of external signal reception conditions such as gravity factors,light factors and salt concentration affects to regulation of PINs protein are unclear.Therefore,it is of great significance to study the relationship between the auxin transporter and abiotic stress in tomato.In this paper,the tomato PIN gene family was identified in the genome data of tomato,which acquired genes was comprehensive analysed.Based on the gene expression pattern under abiotic stress,we screened the genes related to stress resistance and verified the gene silencing function of SlPIN1 gene.The results are as follows:(1)Through the excavation and identification of the tomato PIN gene family members,a total of 10 members were obtained.The evolutionary analysis results showed that 10 members were divided into two categories.PINs according to the known Arabidopsis thaliana,rice and sorghum PIN protein family as reference sequences.The secondary structure of SlPIN proteins was highly similar.Motif analysis showed that there was a conserved structure of NPXXY in motif 3,which played an important role in the interaction between receptor protein and membrane protein in endocytosis.(2)The tissue specificity of tomato PIN genes were analysised by using the qRT-PCR technique.It was found that SlPIN2 was only expressed in roots and other members were expressed in roots,stems,leaves,flowers and fruit tissues,but there are differences in the tendency of up-regulation and downregulation The expression of SlPIN1,SlPIN5,SlPIN8 and SlPIN9 in the root is greater than that in stem,leaf,flower and fruit and the expression of SlPIN3 in the flower was highest.(3)Tomato seedlings were treated with abiotic stress and analyzed the responses of 9 members to abiotic stress in leaves(SlPIN2 was only expressed in roots).The results showed that the expression of 9 SlPIN genes had different degrees of response and up-regulation and down-regulation phenomenon under low temperature,drought and salinity.The variation of gene expression was smaller under salt stress.SlPIN1,SlPIN3,SlPIN4,SlPIN5,SlPIN6 and SlPIN9 are all up-regulated under the condition of low temperature treatment.The expression of SlPIN1,SlPIN6,SlPIN7,SlPIN8 and SlPIN10 were also up-regulated under drought treatment.(4)Phenotypic observation and physiological and biochemical analysis of TRV-SlPIN1 plants with silent success were carried out.The ABA content of the silenced plants was significantly lower than that of the control plants.The MDA content of the silenced plants was significantly higher than that of the control,while the proline content and SOD activity decreased significantly under the drought conditions,which indicating that the down regulated expression of the gene reduced the drought resistance of tomato plants.