| Nitric oxide(NO) is a free radical gas formed endogenously in many biology systems including animal,plants and microbes,in which it performs a wide range of biological activities. The role of NO in animal and microbes has been studied quite clearly,however the study of NO in plant is just at the beginning.In plants,NO as a central signaling molecule plays a regulatory role in plant growth,development and defense responses,including stimulation of seed germination,regulation of root and xylem development,modulation of plant growth and development,plant maturation and senescence,suppression of floral transition,mediation of stomatal movement,involvement of light-mediated greening.Accumulating evidence suggests that NO acts as a key signal role in the plant response to biotic and abiotic stress.Most important,many researches indicate that interaction between NO and phytohormone is widespread.In the study,screening for NO related mutants in Arabidopsis thaliana,NO-sensitive mutant F27 was isolated by root inhibition effect of 50μM NO donor(sodium-nitroprussiate,SNP). Under the influence of NO,the root length of mutant F27 was much shorter than wild type,while the inhibition of the mutant's root was more serious according to rising consistency of NO, whose phenotype was stable via genetic anaylsis.It's also found that the germination rate of the mutant was inhibited by ABA,demonstrating F27 was sensitive to ABA at the same time.So obtain of this mutation could provide an effective tool for study the relationship between NO and other phytohormones.In addition,genetic analysis shows that the mutant was caused by single recessive gene mutation.Through the nap-based cloning technique,the mutation was positioned to the 5th chromosome of Arabidopsis.Finally,the range of mutation point was from 100.2 cM to 100.4cM on Genetic Map,and narrow in 25kb on Physics Map,including 3 genes and the 10kb region. Screening the T-DNA mutant of these 3 genes,the similar phenotype to ABA was found.
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