An official website of the United States government
ABSTRACT Miscanthusholds a promise as a biocrop due to its high yield, perenniality and ability to grow on infertile soils. However, the current commercial biomass production ofMiscanthusis mostly limited to a single sterile triploid clone ofM.×giganteus. Nevertheless, parental species ofM.×giganteus, MiscanthussacchariflorusandMiscanthussinensiscontain vast genetic diversity for crop improvement. WithM. sacchariflorushaving a natural geographic distribution in cold‐temperate northeast China and eastern Russia, we hypothesised that it has substantial variation in physiological response to chilling. Using a semi‐high‐throughput method, we phenotyped 209M. sacchariflorusgenotypes belonging to six genetic groups for non‐photochemical quenching (NPQ) and photosystem II efficiency (ΦPSII) kinetics under warm and chilling treatments in three growing seasons. In response to the chilling treatment, all genetic groups exhibited an increase in NPQ induction rate indicating faster activation of NPQ in light. Notably, under chilling, the Korea/NE China/Russia 2x and N China 2x groups stood out for the highest NPQ rate in light and the highest steady‐state NPQ in light. This NPQ phenotype may contribute adaptation to chilling during bright, cold mornings of spring and early autumn in temperate climates, when faster NPQ would better protect from oxidative stress. Such enhanced adaptation could expand the growing season and thus productivity at a given location or expand the range of economically viable growing locations to higher latitudes and altitudes. A genome‐wide association study identified 126 unique SNPs associated with NPQ and ΦPSII traits. Among the identified candidate genes were enzymes involved in the ascorbate recycle and shikimate pathway, gamma‐aminobutyric acid and cation efflux transporters. Identifying natural variation and genes involved in NPQ and ΦPSII kinetics considerably enlarges the toolbox for breeding and/or engineeringMiscanthuswith optimised photosynthesis under warm and chilling conditions for sustainable feedstock production for bioenergy. Chilling affects the productivity and geographical distribution of most crops. Using a semi‐high‐throughput approach to investigate photosynthesis‐related traits, we characterised variation existing in the bioenergy cropMiscanthusunder chilling and warm conditions and identified potential genes associated with it. Under chilling, two genetic groups from the northern edge ofMiscanthusdistribution stood out for faster activation of photoprotection. This trait may contribute adaptation to chilling in temperate climates, when faster photoprotection would better defend from oxidative stress. Enhanced chilling adaptation could expand the growing season and thus productivity or enlarge the range of growing locations.
more »
« less
This content will become publicly available on January 3, 2026
Exploring chilling stress and recovery dynamics in C4 perennial grass of Miscanthus sinensis
The increasing cultivation of perennial C4 grass known asMiscanthus spp. for biomass production holds promise as a sustainable source of renewable energy. Unlike the sterile triploid hybrid ofM. ×giganteus, which cannot reproduce through seeds,M.sinensispossesses attributes that could potentially address these limitations by effectively establishing itself through seed propagation. This study aimed to investigate how 18 genotypes ofM.sinensisrespond to chilling stress and subsequent recovery. Various traits were measured, including growth and biomass yield, the rate of leaf elongation, and a variety of chlorophyll fluorescence parameters, as well as chlorophyll content estimated using the SPAD method. Principal Component Analysis revealed unique genotype responses to chilling stress, with distinct clusters emerging during the recovery phase. Strong, positive correlations were identified between biomass content and yield-related traits, particularly leaf length. Leaf growth analysis delineated two subsets of genotypes: those maintaining growth and those exhibiting significant reductions under chilling conditions. The Comprehensive Total Chill Stress Response Index (SRI) pinpointed highly tolerant genotypes such as Ms16, Ms14, and Ms9, while Ms12 showed relatively lower tolerance.
more »
« less
- Award ID(s):
- 2142993
- PAR ID:
- 10574342
- Editor(s):
- Ghasemi-Soloklui, Ali Akbar
- Publisher / Repository:
- Public Library of Science
- Date Published:
- Journal Name:
- PLOS ONE
- Volume:
- 20
- Issue:
- 1
- ISSN:
- 1932-6203
- Page Range / eLocation ID:
- e0308162
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
More Like this
-
-
The increase in intensity and frequency of drought due to global climate change has increased the urgency of developing crop cultivars suitable for dry environments. Drought tolerance is a complex trait that involves numerous physiological, biochemical, and morphological responses. A better understanding of those mechanisms is critical to develop drought tolerant cultivars. In this study, we aimed to understand the morphophysiological changes at the shoot and root levels in response to drought stress of ten oat genotypes with diverse root morphological characteristics. Twenty-one-day old plants were subjected to drought stress in a greenhouse by withholding water for two weeks. Several characteristics including chlorophyll content, relative water content (RWC), stomatal conductance, stomata number, shoot dry weight (SDW), root dry weight (RDW), root-to-shoot biomass ratio (RSR), root length, root area, and root volume were measured on well-watered, and drought-stressed plants. Grain yield was evaluated by continuing the drought treatment with a drying and rewatering cycle every 15 days until physiological maturity. The water regime had a significant impact on all traits evaluated. A significant interaction between genotype and water treatment was observed for RWC, chlorophyll content, stomatal conductance, stomata number, and grain yield but not for root traits, suggesting that the root system of all genotypes responded similarly to drought stress. Hayden, the cultivar with the lowest reduction in grain yield from the drought treatment, was among the genotypes with the lowest reduction in RWC and chlorophyll content but with a sharp decrease in stomata number, thus indicating that regulating the plant water status and maintaining the photosynthesis level are important for oat plants to maintain grain yield under drought stress. The size of the root system was not correlated with grain yield under drought, but the RWC and grain yield were significantly correlated under drought, thus suggesting that maintaining the RWC is an important characteristic for oat plants to maintain yield under drought stress.more » « less
-
Abstract Despite long‐standing theory for classifying plant ecological strategies, limited data directly link organismal traits to whole‐plant growth rates (GRs). We compared trait‐growth relationships based on three prominent theories: growth analysis, Grime's competitive–stress tolerant–ruderal (CSR) triangle, and the leaf economics spectrum (LES). Under these schemes, growth is hypothesized to be predicted by traits related to relative biomass investment, leaf structure, or gas exchange, respectively. We also considered traits not included in these theories but that might provide potential alternative best predictors of growth. In phylogenetic analyses of 30 diverse milkweeds (Asclepiasspp.) and 21 morphological and physiological traits, GR (total biomass produced per day) varied 50‐fold and was best predicted by biomass allocation to leaves (as predicted by growth analysis) and the CSR traits of leaf size and leaf dry matter content. Total leaf area (LA) and plant height were also excellent predictors of whole‐plant GRs. Despite two LES traits correlating with growth (mass‐based leaf nitrogen and area‐based leaf phosphorus contents), these were in the opposite direction of that predicted by LES, such that higher N and P contents corresponded to slower growth. The remaining LES traits (e.g., leaf gas exchange) were not predictive of plant GRs. Overall, differences in GR were driven more by whole‐plant characteristics such as biomass fractions and total LA than individual leaf‐level traits such as photosynthetic rate or specific leaf area. Our results are most consistent with classical growth analysis—combining leaf traits with whole‐plant allocation to best predict growth. However, given that destructive biomass measures are often not feasible, applying easy‐to‐measure leaf traits associated with the CSR classification appear more predictive of whole‐plant growth than LES traits. Testing the generality of this result across additional taxa would further improve our ability to predict whole‐plant growth from functional traits across scales.more » « less
-
Muller, Bertrand (Ed.)Abstract Maintaining crop productivity is challenging as population growth, climate change, and increasing fertilizer costs necessitate expanding crop production to poorer lands whilst reducing inputs. Enhancing crops’ nutrient use efficiency is thus an important goal, but requires a better understanding of related traits and their genetic basis. We investigated variation in low nutrient stress tolerance in a diverse panel of cultivated sunflower genotypes grown under high and low nutrient conditions, assessing relative growth rate (RGR) as performance. We assessed variation in traits related to nitrogen utilization efficiency (NUtE), mass allocation, and leaf elemental content. Across genotypes, nutrient limitation generally reduced RGR. Moreover, there was a negative correlation between vigor (RGR in control) and decline in RGR in response to stress. Given this trade-off, we focused on nutrient stress tolerance independent of vigor. This tolerance metric correlated with the change in NUtE, plasticity for a suite of morphological traits, and leaf element content. Genome-wide associations revealed regions associated with variation and plasticity in multiple traits, including two regions with seemingly additive effects on NUtE change. Our results demonstrate potential avenues for improving sunflower nutrient stress tolerance independent of vigor, and highlight specific traits and genomic regions that could play a role in enhancing tolerance.more » « less
-
ABSTRACT Climate means and variability are shifting rapidly, leading to mismatches between climate and locally adapted plant traits. Phenotypic plasticity, the ability of a plant to respond to environmental conditions within a lifetime, may provide a buffer for plants to persist under increasing temperature and water stress. We used two reciprocal common gardens across a steep temperature gradient to investigate plasticity in six populations of Fremont cottonwood, an important foundation tree species in arid riparian ecosystems. We investigated two components of leaf hydraulic architecture: Leaf venation and stomatal morphology, both of which regulate leaf water potential and photosynthesis. These traits will likely affect plant performance under climate stressors, but it is unclear whether they are controlled by genetic or environmental factors and whether they respond to the environment in parallel or independent directions. We found that: (1) Populations had divergent responses to a hotter growing environment, increasing or decreasing vein density. (2) Populations showed surprisingly independent responses of venation vs. stomatal traits. (3) As a result of these different responses, plasticity in hydraulic architecture traits was not predictable from historic climate conditions at population source locations and often varied substantially within populations. (4) Hydraulic architecture was clearly linked to growth, with higher vein and stomatal density predicting greater tree growth in the hottest growing environment. However, higher plasticity in these traits did not increase average growth across multiple environments. Thus,P. fremontiipopulations and genotypes vary in their capacity to adjust their leaf hydraulic architecture and support growth in contrasting environments, but this plasticity is not clearly predictable or beneficial. Identifying genotypes suitable for future conditions will depend on the relative importance of multiple traits and on both evolutionary and ecological responses to changing temperature and water availability.more » « less
