Abstract
BackgroundNewly formed polyploids may experience short-term adaptative changes in their genome that may enhance the resistance of plants to stress. Considering the increasingly serious effects of drought on biofuel plants, whole genome duplication (WGD) may be an efficient way to proceed with drought resistant breeding. However, the molecular mechanism of drought response before/after WGD remains largely unclear.ResultWe found that autoploid switchgrass (Panicum virgatum L.) 8X Alamo had higher drought tolerance than its parent amphidiploid 4X Alamo using physiological tests. RNA and microRNA sequencing at different time points during drought were then conducted on 8X Alamo and 4X Alamo switchgrass. The specific differentially expressed transcripts (DETs) that related to drought stress (DS) in 8X Alamo were enriched in ribonucleoside and ribonucleotide binding, while the drought-related DETs in 4X Alamo were enriched in structural molecule activity. Ploidy-related DETs were primarily associated with signal transduction mechanisms. Weighted gene co-expression network analysis (WGCNA) detected three significant DS-related modules, and their DETs were primarily enriched in biosynthesis process and photosynthesis. A total of 26 differentially expressed microRNAs (DEmiRs) were detected, and among them, sbi-microRNA 399b was only expressed in 8X Alamo. The targets of microRNAs that were responded to polyploidization and drought stress all contained cytochrome P450 and superoxide dismutase genes.ConclusionsThis study explored the drought response of 8X and 4X Alamo switchgrass on both physiological and transcriptional levels, and provided experimental and sequencing data basis for a short-term adaptability study and drought-resistant biofuel plant breeding.
Highlights
Formed polyploids may experience short-term adaptative changes in their genome that may enhance the resistance of plants to stress
Detection of drought tolerance of tetraploid and octoploid switchgrass Six drought resistant physiological indices were investigated under four different time points of drought stress by one-way ANOVA (SPSS 20.0) to detect the drought tolerance of autopolyploid switchgrass (8X Alamo) and its parental amphidiploid (4X Alamo) (Fig. 1)
In 4X Alamo, the POD activity was lower in drought stressed plants than in CK plants, but 8X Alamo had higher POD activity at 6 and 18 days in Drought stress (DS) plant compared to CK plants. (Fig. 1b)
Summary
Formed polyploids may experience short-term adaptative changes in their genome that may enhance the resistance of plants to stress. Considering the increasingly serious effects of drought on biofuel plants, whole genome duplication (WGD) may be an efficient way to proceed with drought resistant breeding. Switchgrass (Panicum virgatum L.), as a well-known bioenergy crop found on marginal lands [1], has a substantial potential to help relieve the world energy shortage [2]. It does not just have the dual purposes as a forage and energy crop [3], but it is even able to improve. Recent studies have found that drought is a major limitation for biofuel production [5], and breeding objectives for switchgrass should address the enhancement of drought resistance. Wide ranging studies on physiology, morphology and gene expression suggest that polyploidization can result in plants with increased amount of drought resistance [10,11,12,13]
Sign-in/Register to view highlights & summary 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 callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
