Dataset Information

Leaf size variations in a dominant desert shrub, Reaumuria soongarica, adapted to heterogeneous environments

ABSTRACT: Abstract The climate in arid Central Asia (ACA) has changed rapidly in recent decades, but the ecological consequences of this are far from clear. To predict the impacts of climate change on ecosystem functioning, greater attention should be given to the relationships between leaf functional traits and environmental heterogeneity. As a dominant constructive shrub widely distributed in ACA, Reaumuria soongarica provided us with an ideal model to understand how leaf functional traits of desert ecosystems responded to the heterogeneous environments of ACA. Here, to determine the influences of genetic and ecological factors, we characterized species?wide variations in leaf traits among 30 wild populations of R. soongarica and 16 populations grown in a common garden. We found that the leaf length, width, and leaf length to width ratio (L/W) of the northern lineage were significantly larger than those of other genetic lineages, and principal component analysis based on the in situ environmental factors distinguished the northern lineage from the other lineages studied. With increasing latitude, leaf length, width, and L/W in the wild populations increased significantly. Leaf length and L/W were negatively correlated with altitude, and first increased and then decreased with increasing mean annual temperature (MAT) and mean annual precipitation (MAP). Stepwise regression analyses further indicated that leaf length variation was mainly affected by latitude. However, leaf width was uncorrelated with altitude, MAT, or MAP. The common garden trial showed that leaf width variation among the eastern populations was caused by both local adaptation and phenotypic plasticity. Our findings suggest that R. soongarica preferentially changes leaf length to adjust leaf size to cope with environmental change. We also reveal phenotypic evidence for ecological speciation of R. soongarica. These results will help us better understand and predict the consequences of climate change for desert ecosystem functioning. The variations in leaf size along environmental gradients within the species range of Reaumuria soongarica were investigated. Our study shows that there are significant differentiations of leaf size and environmental conditions between genetic lineages in this species. Leaf width variations in heterogeneous environments are partly affected by local adaptation and this shrub preferentially changes leaf length to adjust leaf size to cope with environmental change.

SUBMITTER: Fan X

PROVIDER: S-EPMC7520190 | biostudies-literature | 2020 Aug

REPOSITORIES: biostudies-literature

ACCESS DATA

Similar Datasets

Project description:Hybrid speciation plays an important role in species diversification. The establishment of reproductive isolation is crucial for hybrid speciation, and the identification of diverse types of hybrids, particularly homoploid hybrid species, contributes to a comprehensive understanding of this process. Reaumuria songarica is a constructive shrub widespread in arid Central Asia. Previous studies have inferred that the R. songarica populations in the Gurbantunggut Desert (GuD) originated from homoploid hybridizations between its eastern and western lineages and may have evolved into an incipient species. To further elucidate the genetic composition of different hybrid populations and to determine the species boundary of this hybrid lineage, we investigated the overall phylogeographic structure of R. songarica based on variation patterns of five cpDNA and one nrITS sequences across 32 populations. Phylogenetic analyses demonstrated that within the GuD lineage, the Wuerhe population evolved directly from ancestral lineages, whereas the others originated from hybridizations between the eastern and western lineages. PCoA and genetic barrier analysis supported the subdivision of the GuD lineage into the southern (GuD-S) and northern (GuD-N) groups. Populations in the GuD-S group had a consistent genetic composition and the same ancestral female parent, indicating that they belonged to a homoploid hybrid lineage. However, the GuD-N group experienced genetic admixture of the eastern and western lineages on nrITS and cpDNA, with some populations inferred to be allopolyploid based on ploidy data. Based on cpDNA haplotypes, BEAST analyses showed that the GuD-S and GuD-N groups originated after 0.5 Ma. Our results suggest that multiple expansions and contractions of GuD, driven by Quaternary climatic oscillations and the Kunlun-Yellow River tectonic movement, are important causes of the complex origins of R. songarica populations in northern Xinjiang. This study highlights the complex origins of the Junggar Basin flora and the underappreciated role of hybridization in increasing its species diversity.

Project description:Convergence is commonly caused by environmental filtering, severe climatic conditions and local disturbance. The basic aim of the present study was to understand the pattern of leaf traits across diverse desert plant species in a common garden, in addition to determining the effect of plant life forms (PLF), such as herb, shrub and subshrub, phylogeny and soil properties on leaf traits. Six leaf traits, namely carbon (C), nitrogen (N), phosphorus (P), potassium (K), ?13C and leaf water potential (LWP) of 37 dominant desert plant species were investigated and analyzed. The C, N, K and ?13C concentrations in leaves of shrubs were found higher than herbs and subshrubs; however, P and LWP levels were higher in the leaves of subshrubs following herbs and shrubs. Moreover, leaf C showed a significant positive correlation with N and a negative correlation with ?13C. Leaf N exhibited a positive correlation with P. The relationship between soil and plant macro-elements was found generally insignificant but soil C and N exhibited a significant positive correlation with leaf P. Taxonomy showed a stronger effect on leaf C, N, P and ?13C than soil properties, explaining >50% of the total variability. C3 plants showed higher leaf C, N, P, K and LWP concentration than C4 plants, whereas C4 plants had higher ?13C than C3 plants. Legumes exhibited higher leaf C, N, K and LWP than nonlegumes, while nonlegumes had higher P and ?13C concentration than legumes. In all the species, significant phylogenetic signals (PS) were detected for C and N and nonsignificant PS for the rest of the leaf traits. In addition, these phylogenetic signals were found lower (K-value < 1), and the maximum K-value was noted for C (K = 0.35). The plants of common garden evolved and adapted themselves for their survival in the arid environment and showed convergent variations in their leaf traits. However, these variations were not phylogenetics-specific. Furthermore, marks of convergence found in leaf traits of the study area were most likely due to the environmental factors.

Project description:The pattern of resource allocation to reproduction vs. vegetative growth is a core component of a plant's life-history strategy. Plants can modify their biomass allocation patterns to adapt to contrasting environments. Meristems can have alternative fates to commit to vegetative growth, reproduction, or remaining inactive (dormant or senescent/dead). However, knowledge about whether meristem fates can interpret adaptive changes in biomass allocation remains largely unknown. We measured aboveground plant biomass (a proxy of plant size) and meristem number of a dominant shrub Artemisia ordosica in three populations occupying different habitats in the Mu Us Desert of northern China. Size-dependent biomass allocation and meristem allocation among habitats were compared. The size-dependent biomass allocation and meristem allocation of A. ordosica strongly varied across habitats. There were significant positive linear relationships between meristem allocation and biomass allocation in all habitats, indicating that meristem allocation is an indicator of the estimated resource allocation to reproductive and vegetative organs in this species. Plasticity in meristem allocation was more likely caused by larger individuals having less active meristems due to environmental stress. Vegetative meristems (VM) were likely more vulnerable to environmental limitation than reproductive ones, resulting in the ratio of resource investment between vegetative and reproductive functions exhibiting plasticity in different habitats. A. ordosica invested a higher fraction of its resource to reproduction in the adverse habitat, while more resource to vegetative growth in the favorable habitat. A. ordosica adopts different resource allocation patterns to adapt to contrasting habitat conditions through altering its meristem fates. Our results suggest that the arid-adapted shrub A. ordosica deactivates more VM than reproductive ones to hedge against environmental stress, representing an important adaptive strategy. This information contributes to understand the life-history strategies of long-lived plants under stressful environments.

Project description:BackgroundArtemisia sphaerocephala, a semi-shrub belonging to the Artemisia genus of the Compositae family, is an important pioneer plant that inhabits moving and semi-stable sand dunes in the deserts and steppes of northwest and north-central China. It is very resilient in extreme environments. Additionally, its seeds have excellent nutritional value, and the abundant lipids and polysaccharides in the seeds make this plant a potential valuable source of bio-energy. However, partly due to the scarcity of genetic information, the genetic mechanisms controlling the traits and environmental adaptation capacity of A. sphaerocephala are unknown.ResultsHere, we present the first in-depth transcriptomic analysis of A. sphaerocephala. To maximize the representation of conditional transcripts, mRNA was obtained from 17 samples, including living tissues of desert-growing A. sphaerocephala, seeds germinated in the laboratory, and calli subjected to no stress (control) and high and low temperature, high and low osmotic, and salt stresses. De novo transcriptome assembly performed using an Illumina HiSeq 2500 platform resulted in the generation of 68,373 unigenes. We analyzed the key genes involved in the unsaturated fatty acid synthesis pathway and identified 26 A. sphaerocephala fad2 genes, which is the largest fad2 gene family reported to date. Furthermore, a set of genes responsible for resistance to extreme temperatures, salt, drought and a combination of stresses was identified.ConclusionThe present work provides abundant genomic information for functional dissection of the important traits of A. sphaerocephala and contributes to the current understanding of molecular adaptive mechanisms of A. sphaerocephala in the desert environment. Identification of the key genes in the unsaturated fatty acid synthesis pathway could increase understanding of the biological regulatory mechanisms of fatty acid composition traits in plants and facilitate genetic manipulation of the fatty acid composition of oil crops.

Dataset Information

Leaf size variations in a dominant desert shrub, Reaumuria soongarica, adapted to heterogeneous environments

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets