Abstract
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. Higher levels of antioxidant enzyme activity, reactive oxygen and major reductions in photosynthesis-related markers were suggested for oats at high altitudes. 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 altitudes in which 5,203 up-regulated and 6,436 down-regulated. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment tests were conducted and a group of major high altitude-responsive pigment metabolism genes, photosynthesis, hormone signaling, and cutin, suberine and wax biosynthesis were excavated. Using quantitative real-time polymerase chain response, we also confirmed expression levels of 20 DEGs (qRT-PCR). 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 stress. These new findings contribute to our deeper relevant researches on high altitude stresses and further exploring new candidategenes for adapting plateau environment oat molecular breeding.
Highlights
Extreme environments provide natural laboratories for studies on the processes of speciation and adaptive evolution of organisms (Qiao et al, 2015)
The physiological and agronomical results showed that oats displayed significant increases in MDA, superoxide dismutase (SOD) and soluble sugar contents, accompanied by decreases in chlorophyll, non-photochemical quenching coefficient (NPQ), stomatal density, and hay yield
The transcriptomic profiles showed apparent differences between low and high altitudes where many pathways associated with high altitude stresses were identified including photosynthetic pigment synthesis, photosynthesis, and plant hormone signaling transduction pathways
Summary
Extreme environments provide natural laboratories for studies on the processes of speciation and adaptive evolution of organisms (Qiao et al, 2015). The Qinghai-Tibetan Plateau environment is known for its harsh conditions, characterized by severe coldness, intensive ultraviolet radiations, hypoxia, poor soils and low CO2 pressure (Xin et al, 2011; Jia et al, 2017). The survival in Qinghai-Tibetan Plateau is very challenging for most organisms. Many plant species can thrive in the cold and hypoxic conditions in high-alpine areas (Storz et al, 2010; Yang et al, 2015). The high-altitudinal gradient can restrict plant growth and reproduction via strong solar UVB radiation, resulting in a reduction of photosynthetic rates by bleaching chlorophyll a (Chl a) and damaging the photosynthetic apparatus (Zhu and Yang, 2015). Some alpine plants are able to activate antioxidants such as APX, CAT, GR, proline and abscisic acid to confer plants with the tolerance to the alpine environments (Ch, 2005; Vinocur and Altman, 2005; Li et al, 2014)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
