Comparative Transcriptome Profiling of Two Tibetan Wild Barley Genotypes in Responses to Low Potassium

Abstract

Potassium (K) deficiency is one of the major factors affecting crop growth and productivity. Development of low-K tolerant crops is an effective approach to solve the nutritional deficiency in agricultural production. Tibetan annual wild barley is rich in genetic diversity and can grow normally under poor soils, including low-K supply. However, the molecular mechanism about low K tolerance is still poorly understood. In this study, Illumina RNA-Sequencing was performed using two Tibetan wild barley genotypes differing in low K tolerance (XZ153, tolerant and XZ141, sensitive), to determine the genotypic difference in transcriptome profiling. We identified a total of 692 differentially expressed genes (DEGs) in two genotypes at 6 h and 48 h after low-K treatment, including transcription factors, transporters and kinases, oxidative stress and hormone signaling related genes. Meanwhile, 294 low-K tolerant associated DEGs were assigned to transporter and antioxidant activities, stimulus response, and other gene ontology (GO), which were mainly involved in starch and sucrose metabolism, lipid metabolism and ethylene biosynthesis. Finally, a hypothetical model of low-K tolerance mechanism in XZ153 was presented. It may be concluded that wild barley accession XZ153 has a higher capability of K absorption and use efficiency than XZ141 under low K stress. A rapid response to low K stress in XZ153 is attributed to its more K uptake and accumulation in plants, resulting in higher low K tolerance. The ethylene response pathway may account for the genotypic difference in low-K tolerance.

De novo transcriptome analysis of tobacco seedlings and identification of the early response gene network under low-potassium stress

“…This result is similar to that obtained for rice (Shankar et al, 2013). Most K + transporters of wild barley increased after a 48 h low-potassium treatment (Zeng et al, 2014). Perhaps the transcription levels of K + transporters and K + channels were not significantly affected for short durations under low-potassium treatment.…”

“…Now, the next-generation sequencing method RNA-seq can provide a large amount of expressed sequence tags and transcript expression information between samples (Vanverk et al, 2013). This technique has been applied in studies of plant responses to various abiotic stressors (Postnikova et al, 2013;Zeng et al, 2014).…”

Identification of the proteins associated with low potassium tolerance in cultivated and Tibetan wild barley

“…After 10 days of germination, uniform seedlings were transplanted into plastic pots (5 L) for hydroponic incubation. The experiment was conducted in a greenhouse with aerated hydroponic solution according to Zeng et al [29]. Plants were supplied with a half-strength hydroponic solution in the first week and then changed into a full strength solution, and renewed every five days.…”

Comparative transcriptome profiling of Arabidopsis Col-0 in responses to heat stress under different light conditions

“…After HCL, two software, DAVID (http://david.abcc.ncifcrf.gov/) and GOEAST (http://omicslab.genetics.ac.cn/GOEAST/) enabling integration of data from transcriptomics, were used to conduct gene functional annotation and enrichment analysis. They could also be used for data analysis and exploration because large gene lists could be uploaded and queried (Zeng et al 2014). …”