Comparison between the Transcriptomes of ‘KDML105’ Rice and a Salt-Tolerant Chromosome Segment Substitution Line

摘要

‘KDML105’ rice, known as jasmine rice, is grown in northeast Thailand. The soil there has high salinity, which leads to low productivity. Chromosome substitution lines (CSSLs) with the ‘KDML105’ rice genetic background were evaluated for salt tolerance. CSSL18 showed the highest salt tolerance among the four lines tested. Based on a comparison between the CSSL18 and ‘KDML105’ transcriptomes, more than 27,000 genes were mapped onto the rice genome. Gene ontology enrichment of the significantly differentially expressed genes (DEGs) revealed that different mechanisms were involved in the salt stress responses between these lines. Biological process and molecular function enrichment analysis of the DEGs from both lines revealed differences in the two-component signal transduction system, involving , which encodes phototropin 2 ( ), and , which encodes pyruvate dehydrogenase kinase (PDK), the enzyme that inhibits pyruvate dehydrogenase in respiration. expression was maintained in CSSL18 under salt stress, whereas it was significantly decreased in ‘KDML105’, suggesting OsPHOT2 signaling may be involved in salt tolerance in CSSL18. expression was induced only in ‘KDML105’. These results suggested respiration was more inhibited in ‘KDML105’ than in CSSL18, and this may contribute to the higher salt susceptibility of ‘KDML105’ rice. Moreover, the DEGs between ‘KDML105’ and CSSL18 revealed the enrichment in transcription factors and signaling proteins located on salt-tolerant quantitative trait loci (QTLs) on chromosome 1. Two of them, and , showed the potential to be involved in salt stress response, especially, , whose orthologous genes in had the potential role in photosynthesis adaptation under salt stress.