Physiological and transcriptional response to drought stress among bioenergy grass Miscanthus species

Abstract

Background Miscanthus is a commercial lignocellulosic biomass crop owing to its high biomass productivity, resilience and photosynthetic capacity at low temperature. These qualities make Miscanthus a particularly good candidate for temperate marginal land, where yields can be limited by insufficient or excessive water supply. Differences in response to water stress have been observed among Miscanthus species, which correlated to origin. In this study, we compared the physiological and molecular responses among Miscanthus species under excessive (flooded) and insufficient (drought) water supply in glasshouse conditions. Results A significant biomass loss was observed under drought conditions in all genotypes. M. x giganteus showed a lower reduction in biomass yield under drought conditions compared to the control than the other species. Under flooded conditions, biomass yield was as good as or better than control conditions in all species. 4389 of the 67,789 genes (6.4%) in the reference genome were differentially expressed during drought among four Miscanthus genotypes from different species. We observed the same biological processes were regulated across Miscanthus species during drought stress despite the DEGs being not similar. Upregulated differentially expressed genes were significantly involved in sucrose and starch metabolism, redox, and water and glycerol homeostasis and channel activity. Multiple copies of the starch metabolic enzymes BAM and waxy GBSS-I were strongly up-regulated in drought stress in all Miscanthus genotypes, and 12 aquaporins (PIP1, PIP2 and NIP2) were also up-regulated in drought stress across genotypes. Conclusions Different phenotypic responses were observed during drought stress among Miscanthus genotypes from different species, supporting differences in genetic adaption. The low number of DEGs and higher biomass yield in flooded conditions supported Miscanthus use in flooded land. The molecular processes regulated during drought were shared among Miscanthus species and consistent with functional categories known to be critical during drought stress in model organisms. However, differences in the regulated genes, likely associated with ploidy and heterosis, highlighted the value of exploring its diversity for breeding.

Investigating applied drought in Miscanthus sinensis; sensitivity, response mechanisms, and subsequent recovery

“…Other quantified free amino acids revealed substantial stress-induced changes in their contents. Among those reporting a large increment, serine (Ser) was second only to Pro in its increase (Figure 3a), contrary to the reported downregulation of Ser metabolism in miscanthus leaves under drought, by De Vega et al (2021) transcriptomics analyses. This could be a form of a negative feedback control to reverse its stress-induced accumulation to almost toxic levels.…”

“…Accordingly, exploiting M. sinensis ample genetic diversity via comparative studies, is pivotal in screening for better performing genotypes and the consequent breeding efforts toward improved tolerance in this crop (Weng et al, 2022). This was evident in the dissimilar impact of water-deficiency (Van Der Weijde et al, 2017b) and salt (Chen et al, 2017) on diverse populations of M. sinensis genotypes, and likewise the differential expression of common regulatory pathways after flooding and drought treatments (De Vega et al, 2021).…”

“…This was evident in the dissimilar impact of water‐deficiency (Van Der Weijde et al, 2017b) and salt (Chen et al, 2017) on diverse populations of M . sinensis genotypes, and likewise the differential expression of common regulatory pathways after flooding and drought treatments (De Vega et al, 2021).…”

RNA-Seq Analysis Demonstrates Different Strategies Employed by Tiger Nuts (Cyperus esculentus L.) in Response to Drought Stress

“…Here, the phenylpropanoid biosynthesis (ko00940), as a stress-resistant pathway [ 68 ], was enriched in the KEGG analysis, while the contents of lignin and CAD activities were significantly changed ( Figure 9 ). In addition, the three pathways have been reported to participate in responding to abiotic stress in Hibiscus cannabinus , Miscanthus and tomato ( Solanum lycopersicum ) [ 69 , 70 , 71 ]. Our study demonstrated the mechanisms underlying the drought stress responses by tiger nuts, which enhances drought tolerance.…”

Effect of Forecast Climate Changes on Water Needs of Giant Miscanthus Cultivated in the Kuyavia Region in Poland

“…Due to the fact that in the case of energy crops, the yield is mainly determined by the water factor, in the case of water shortage, the cultivation of plantations becomes economically unjustified. Therefore, it is important to recognize the impact of water deficit on plant growth and development [14][15][16][17].…”