Studies On Breaking The Dormancy Of Tibetan Wild Barley

Seed dormancy is important for plants to adapt to natural environment,making them successfully spread into a vast area with harsh circumstances.Tibetan wild barley,orginated from the Tibetan Pleteau,is one of the special genetic resources with great genetic diversity for barley improvement.Seed dormancy is regulated by complex internal signal interactions and has not been fully understood,including dormancy of Tibetan wild barley.Herein,transcriptome and metabolome are used to study the mechanism of dormancy breaking underlying the role of after-ripening or cold stratification.The major results were summaried as follows:1.Responses of the Tibetan wild barley seeds to after-ripening and cold strification6 different Tibetan wild barley genotypes showed significant increase in germination rate and decrease in dormancy under either cold strification or after-ripening.It indicated that no matter cold strification or after-ripening made effects on dormancy release.During the process of cold strification,6 Tibetan wild barley seeds germinated,showing that some wild barley genotypes were able to germinate in cold temperature.2.Metabolome of Tibetan wild barley under the process of after-ripeningMetabolome analysis was carried out with the Tibetan wild barley seeds under different after-ripening treatment time.It showed that Starch and sucrose metabolism,Glycerophospholipid metabolism and Galactose metabolism played the major roles in dormancy release.One of the most differential metabolites in Glycerophospholipid metabolism,PA,was widely thought to be an intermediate substance controlled by plant phytohormone ABA.3.Gene expression analysis of Tibetan wild barley under the process of cold strification.By analyzing the gene expression under cold strification,it could be found that reduced responses to ABA might be the important reasons why dormancy release happened.Related genes like PYL,PP2 C and Sn RK2 in ABA signaling pathway showed different expressions.So plant phytohormones,especially ABA were also major reason for dormancy release under cold strification.