Integrated physiological and transcriptomic analyses responses to altitude stress in oat (Avena sativa L.)

Abstract Background The oat is an annual gramineous forage grass with the remarkable ability to survive under various stressful environments. However, understanding the effects of high altitude stresses on oats is poor. Therefore, the physiological and the transcriptomic changes were analyzed at two sites with different altitudes, low (ca. 2,080 m) or high (ca. 2,918 m) respectively.Results It was indicated that oats at high altitude showed higher levels of antioxidant enzyme activities and significant decreases in the non-photochemical quenching coefficient,chlorophyll content and stomatal density. Furthermore, oat yields were severely suppressed at the high altitude. RNA-seq results showed that 11,639 differentially expressed genes were detected at both the low and the high altitudesin which 5,203 up-regulated and 6,436 down-regulated. GO and KEGG annotations suggested that many differentially expressed genes be involved in pathways of cellular processes, metabolic processes and plant-pathogen interactions. Furthermore, 125 differentially expressed genes encoding TFs were involved in signal transductions by regulating the resistance genes in oats at high altitude. Some differentially expressed genes related to pigment metabolisms and photosyntheses were differentially expressed suggesting that these genes probably play responsive and regulatory roles in oats under the high altitude stress. Meanwhile, 273 differentially expressed genes related to hormone signaling pathways were significantly enriched in gibberellin, auxin, jasmonic acid and abscisic acid pathways indicating that these genes participated in the processes of oats responding to high altitude stresses.Conclusion In summary, our study generated genome-wide transcript profile and may be useful for understanding the molecular mechanisms of Avena sativa L. in response to high altitude stresses.These new findings contribute to our deeper relevant researches on altitude stresses and further exploring new candidategenes for adapting plateau environment oat molecular breeding.