Saline stress is a major factor that limits crop yield. Nitric oxide (NO) is functional during plant growth, development, and defense responses. In the present study, the protective role of NO in alleviating saline stress in maize at the physiological and proteomic levels was examined. Our results showed that salt treatment quickly induced NO accumulation and addition of the NO donor S-nitroso-N-acetylpenicillamine (SNAP) efficiently eliminated the inhibitory effect of salt on shoot growth and photosynthesis and inhibited salt-inducible H2O2 accumulation. These effects could be reversed by NO metabolic scavengers and inhibitors. Further proteomic and Western blotting analysis revealed that NO induced G-protein-associated protein accumulation and antioxidant enzymes activities, in addition to activation of defense proteins, energy metabolism, and cell structure/division in salt-treated maize seedlings. Controlling the G-protein status with G-protein activators or inhibitors also affected NO generation and root and stem growth in maize seedlings after saline stress. On the basis of these results, we propose that NO enhances salt tolerance in maize seedlings by enhancing antioxidant enzyme activities and controlling H2O2 levels, and these effects are accompanied by diverse downstream defense responses. During this process, G-protein signaling is an early event that works upstream of NO biogenesis.Keywords: maize; nitric oxide; ROS; saline stress;

Elevated temperature and humidity are major environmental factors limiting crop yield and distribution. An understanding of the mechanisms underlying plant tolerance to high temperature and humidity may facilitate the development of cultivars adaptable to warm or humid regions. Under conditions of 90% humidity and 35 °C, the thermotolerant plant Portulaca oleracea exhibits excellent photosynthetic capability and relatively little oxidative damage. To determine the proteomic response that occurs in leaves of P. oleracea following exposure to high temperature and high humidity, a proteomic approach was performed to identify protein changes. A total of 51 differentially expressed proteins were detected and characterized functionally and structurally; these identified proteins were involved in various functional categories, mainly including material and energy metabolism, the antioxidant defense responses, protein destination and storage, and transcriptional regulation. The subset of antioxidant defense-related proteins demonstrated marked increases in activity with exposure to heat and humidity, which led to lower accumulations of H2O2 and O2– in P. oleracea compared with the thermosensitive plant Arabidopsis thaliana. The quickly accumulations of proline content and heat-shock proteins, and depleting abscisic acid (ABA) via increasing ABA-8′-hydroxylase were also found in P. oleracea under stress conditions, that resulted into greater stomata conductance and respiration rates. On the basis of these findings, we propose that P. oleracea employs multiple strategies to enhance its adaptation to high-temperature and high-humidity conditions.Keywords: ABA; high humidity; high temperature; Portulaca oleracea; ROS;

Using a qualitative social research method at the local administrative level, this paper provides insight into the policy process in China and farmers’ perceptions of the effectiveness of policies implemented to deal with drought. Two villages in rural South-West Yunnan were purposefully selected for the study. The research started with the general assumption that China has a strong top-down hierarchal approach to policy processes and that funding dispersal is prioritised by the central government. However, the study found that funding proposals are prioritised for selection in a bottom-up, participatory manner from the local level. The study also found that farmers’ perceptions of the effectiveness of policy implementation were directly related to their past experience. Among the nine indicators used to measure the effectiveness of policy implementation at the local level, the farmers in the study area perceived access to roads as highly effective; water use efficiency projects, market demand, human mobility for jobs, and government funds as moderately effective; drought knowledge, community participation in planning, and governance structures as least effective; and the role of leadership as not effective. The study found that farmers’ adaptation at the local level is oriented towards short-term market rewards and income diversification. Farmers’ local-level adaptation is guided by government priorities and driven by their perception of tangible benefits. To ensure the effectiveness of policy implementation, long-term adaptation strategies, such as awareness raising, capacity building, watershed management, and source conservation need to be strengthened at the local level.

The Qinghai–Tibetan Plateau is biologically diverse, with 9556 species of vascular plants in the 2,500,000 km2 plateau area. We focused on seed plants from the Qinghai–Tibetan Plateau. A total of 9321 species in the Qinghai–Tibetan Plateau were recorded. Sixty-one of these genera are Chinese endemics. Our results suggested that the flora of the Qinghai–Tibetan Plateau was characterized by relatively few polyploids, and aneuploidy was also considered as relatively rare. We inferred that aneuploidy may be affected by environmental factors and the addition or loss of centromeres. Furthermore, the highest frequency of polyploids was found among perennial herbs. Annuals had low polyploidy, and perennials had high polyploidy. Species richness was correlated with the incidence of polyploids, environmental conditions, and reproductive isolation.

Floral traits, including those invisible to humans but visible to pollinators, that increase pollination efficiency may be selected by pollinators in plant species with pollen limitation of seed production, but the importance of pollinators as selective agents on different floral traits needs to be further quantified experimentally. In the present study, we examined selective strength on flower diameter, flower height, UV bulls-eye size, sepal size and UV proportion via female fitness in Caltha scaposa, based on open-pollinated and hand-pollinated flowers, through which pollinator-mediated selection was calculated for each of floral traits. Our results suggest that seed production of C. scaposa is pollen limited in natural conditions. There was directional selection (Δβpollinator = −0.12) for larger flowers in open-pollinated flowers, while no significant selection was found in flower height, UV bulls-eye size, sepal size or UV proportion. Statistically significant selection was found in UV bulls-eye size, sepal size and UV proportion in hand-pollinated flowers, but interactions with pollinators contributed only to flower diameter. We conclude that in C. scaposa, floral traits that are subjected to selection might be driven by multiple selective agents, and suggest the importance of investigating floral traits that are invisible to human but visible to pollinators in measuring pollinator-mediated selection via male fitness.

In higher plants, sugars (mainly sucrose) are produced by photosynthetically assimilated carbon in mesophyll cells of leaves and translocated to heterotrophic organs to ensure plant growth and development. Sucrose transporters, or sucrose carriers (SUCs), play an important role in the long-distance transportation of sucrose from source organs to sink organs, thereby affecting crop yield and quality. The identification, characterization, and molecular function analysis of sucrose transporter genes have been reported for monocot and dicot plants. However, no relevant study has been reported on sucrose transporter genes in Brassica rapa var. rapa, a cruciferous root crop used mainly as vegetables and fodder. We identified and cloned 12 sucrose transporter genes from turnips, named BrrSUC1.1 to BrrSUC6.2 according to the SUC gene sequences of B. rapa pekinensis. We constructed a phylogenetic tree and analyzed conserved motifs for all 12 sucrose transporter genes identified. Real-time quantitative polymerase chain reaction was conducted to understand the expression levels of SUC genes in different tissues and developmental phases of the turnip. These findings add to our understanding of the genetics and physiology of sugar transport during taproot formation in turnips.

SpERF1 acts as a positive regulator, contributing to drought stress tolerance inA. thalianathrough activating DRE/CRT elements in the promoters of abiotic stress-responsive genes.Stipa purpurea is an endemic perennial grass species in alpine arid and semi-arid meadows on the Qinghai-Xizang Plateau, which is highly tolerant against drought and cold. ERF transcription factors are known to regulate gene expression under abiotic and biotic treatments. Herein, we isolated a full-length ERF gene CDS from S. purpurea named SpERF1, which was induced by drought, cold, and jasmonic acid stresses. Subcellular localization revealed that SpERF1 is a nuclear protein, consistent with its roles as a transcription factor. Overexpression of SpERF1 enhanced drought tolerance of transgenic Arabidopsis thaliana via the activation of DRE/CRT elements in the promoters of abiotic stress-responsive genes. Furthermore, increased accumulation of proline indicated that SpERF1 might be involved in proline synthesis in the transgenic lines, allowing them to have a better buffering capacity and membrane protection under drought stress. This study indicated that SpERF1 might be an attractive target in the genetic engineering for improving stress tolerance in other crops. Moreover, SpERF1 protein function analysis increased our understanding of S. purpurea’s ability to adapt to the adverse conditions of the Qinghai-Xizang Plateau.

The purpose of the present study was to characterize SpCBL6 (GenBank accession number: KT780442) from Stipa purpurea and elucidate the function of this protein in abiotic stress. The full-length cDNA of SpCBL6 was isolated from S. purpurea by rapid amplification of cDNA ends methods. Laser confocal microscopy was used to analyze the subcellular localization of SpCBL6. The constructs of 35S:GFP-SpCBL6 was used to transform wild-type (WT) Arabidopsis plants (ecotype Columbia-0) with the floral dip method. Quantitative reverse-transcription PCR (qRT-PCR), water potential, photosynthetic efficiency (Fv/Fm), and ion leakage was performed to investigate the role of SpCBL6 in abiotic stress. The open reading frame of SpCBL6 contains 681 bp nucleotides and encodes a 227-amino acid polypeptide. Phylogenetic analysis indicated that SpCBL6 showed the highest similarity with rice OsCBL6. SpCBL6 transcripts were induced by freezing and drought treatments. Subcellular localization analysis showed that SpCBL6 was located in membrane of protoplast. Overexpression of SpCBL6 in Arabidopsis thaliana demonstrated that the transgenic plants were more tolerant to cold treatment, but less tolerant to drought, compared with the plants. qRT-PCR analysis showed that the drought stress marker genes were inhibited in transgenic plants, whereas the cold stress marker genes were enhanced. Further analysis showed that SpCBL6-overexpressing plants showed enhanced water potential, photosynthetic efficiency (Fv/Fm), and reduced ion leakage compared with the wild-type after cold treatment. Collectively, these results indicate that SpCBL6, a new member of the CBL gene family isolated from S. purpurea, enhances cold tolerance and reduces drought tolerance in plants.

•Comparative proteomic analysis of P. saundersiana at five different altitudes•Antioxidant activity and primary metabolites in alpine plant adaptation•Epigenetic regulation and post-translational modification in alpine plant adaptation•Root architecture and leaf phenotype difference in alpine plant adaptationThis study presents an analysis of leave and rood morphology, biochemical and proteomics approach as adaptation strategies of the alpine plant Potentilla saundersiana in an altitude gradient. Several plant physiological parameter, including root and leaf architecture, leaf photosynthesis capacity, specific leaf area (SLA) and leaf nitrogen concentration, histology and microscopy, anthocyanin and proline contents, antioxidant enzyme activity assay, in-gel enzyme activity staining, H2O2 and O2− content, immunoblotting, auxin and strigolactone content and proteomics analysis were evaluated at five different altitudes. P. saundersiana modulated the root architecture and leaf phenotype to enhance adaptation to alpine environmental stress through mechanisms that involved hormone synthesis and signal transduction, particularly the cross-talk between auxin and strigolactone. Furthermore, an increase of antioxidant proteins and primary metabolites as a response to the alpine environment in P. saundersiana was observed. Proteins associated with the epigenetic regulation of DNA stability and post-translational protein degradation was also involved in this process. Based on these findings, P. saundersiana uses multiple strategies to adapt to the high-altitude environment of the Alpine region.Biological significanceThe alpine environment, which is characterized by sharp temperature shifts, high levels of ultraviolet radiation exposure, and low oxygen content, limits plant growth and distribution. Alpine plants have evolved strategies to survive the extremely harsh conditions prevailing at high altitudes; however, the underlying mechanisms remain poorly understood. The alpine plant Potentilla saundersiana is widespread in the Northwestern Tibetan Plateau. Here we adopted a comparative proteomics approach to investigate the mechanisms by which P. saundersiana withstands the alpine environment by examining plants located at five different altitudes. We detected and functionally characterized 118 proteins spots with variable abundance. Proteins involved in antioxidant activity, primary metabolites, epigenetic regulation, and protein post-translational modification play important roles in conferring tolerance to alpine environments. Furthermore, our results indicate that P. saundersiana modulates the root architecture and leaf phenotype to enhance adaptation to alpine environmental stress. These results provide novel insight into the multiple strategies underlying P. saundersiana adaptation to the high-altitude environment of the Northwestern Tibetan Plateau.This study investigated the adaptation of the alpine plant Potentilla saundersiana to the altitude gradient in the Northwestern Tibetan Plateau. Our proteomics and physiological data demonstrated that P. saundersiana uses multiple strategies to adapt to alpine environmental stress, including 1) modulating root architecture, leaf phenotype, photosynthesis capability, and cell wall structure; 2) regulating primary and secondary metabolites (such as sugar, proline, and flavones) and plant hormone synthesis; 3) activating downstream defense response and antioxidant enzyme activities; and 4) initiating novel proteasome- or autophagy-mediated protein degradation mechanisms. Therefore, we conclude that the alpine plant P. saundersiana evolved multiple strategies to adapt to environmental stress at high altitudes.

We found the novel role of hydrogen sulfide in the adaptation of the alpine plant to altitude gradient in the Northern Tibetan Plateau.Alpine plants have developed strategies to survive the extremely cold conditions prevailing at high altitudes; however, the mechanism underlying the evolution of these strategies remains unknown. Hydrogen sulfide (H2S) is an essential messenger that enhances plant tolerance to environmental stress; however, its role in alpine plant adaptation to environmental stress has not been reported until now. In this work, we conducted a comparative proteomics analysis to investigate the dynamic patterns of protein expression in Lamiophlomis rotata plants grown at three different altitudes. We identified and annotated 83 differentially expressed proteins. We found that the levels and enzyme activities of proteins involved in H2S biosynthesis markedly increased at higher altitudes, and that H2S accumulation increased. Exogenous H2S application increased antioxidant enzyme activity, which reduced ROS (reactive oxygen species) damage, and GSNOR (S-nitrosoglutathione reductase) activity, which reduced RNS (reactive nitrogen species) damage, and activated the downstream defense response, resulting in protein degradation and proline and sugar accumulation. However, such defense responses could be reversed by applying H2S biosynthesis inhibitors. Based on these findings, we conclude that L. rotata uses multiple strategies to adapt to the alpine stress environment and that H2S plays a central role during this process.

Natural selection drives species adaptations to biotic and abiotic stresses. Species distributed along a moisture gradient, such as Stipa purpurea, a dominant grass in alpine arid and semi-arid meadows on the Tibetan Plateau, provide an opportunity to evaluate the effects of long-term adaptation to differing degrees of drought stress on gene expression. However, the genetic basis of this divergence remains largely unknown. Next-generation sequencing technologies have provided important genome-wide insights on the evolution of organisms for which genomic information is lacking. To understand how S. purpurea responds to drought stress, we selected five populations distributed along the degressive rainfall line on the northwestern Tibetan Plateau that currently present evolutionary acclimation to localized drought pressure at the physiological and biochemical levels and compared their transcriptome responses. In addition, we performed de novo assembly of the S. purpurea transcriptome using short read sequencing technology and successfully assembled 84,298 unigenes from approximately 51 million sequencing reads. We quantified gene expression level to compare their transcriptome responses using mRNA-Seq and identified differentially expressed transcripts that are involved in primary and secondary plant metabolism, plant hormone synthesis, defense responses, and cell wall synthesis. Furthermore, physiological and biochemical evidence supports that abscisic acid (ABA) accumulation and cell wall strengthening derived from the differential transcripts contribute to the tolerance of S. purpurea to drought stress. The mechanisms by which S. purpurea adapts to drought stress provide new insight into how plants ecologically adapt and evolve.

Chromosome numbers and karyotypes of 26 Ophiopogon species, 2 Liriope species and 5 Peliosanthes species of the family Liliaceae from Southwest China, were investigated. The study revealed a detailed picture of chromosome features and their pattern of karyotype variation in Ophiopogoneae. Karyotype asymmetry in different species and different populations of the same species varied greatly due to different locality conditions. Our analyses may support the separately monophyly of Ophiopogon, Liriope and Peliosanthes.

While researchers are aware that a mix of Local Ecological Knowledge (LEK), community-based resource management institutions, and higher-level institutions and policies can facilitate pastoralists’ adaptation to climate change, policy makers have been slow to understand these linkages. Two critical issues are to what extent these factors play a role, and how to enhance local adaptation through government support. We investigated these issues through a case study of two pastoral communities on the Tibetan Plateau in China employing an analytical framework to understand local climate adaptation processes. We concluded that LEK and community-based institutions improve adaptation outcomes for Tibetan pastoralists through shaping and mobilizing resource availability to reduce risks. Higher-level institutions and policies contribute by providing resources from outside communities. There are dynamic interrelationships among these factors that can lead to support, conflict, and fragmentation. Government policy could enhance local adaptation through improvement of supportive relationships among these factors. While central government policies allow only limited room for overt integration of local knowledge/institutions, local governments often have some flexibility to buffer conflicts. In addition, government policies to support market-based economic development have greatly benefited adaptation outcomes for pastoralists. Overall, in China, there are still questions over how to create innovative institutions that blend LEK and community-based institutions with government policy making.

Climate change affects various facets of life but there is little data on its effects on wild mushroom fruiting. Yunnan Province in China is a rich source of wild mushrooms and has experienced a temperature rise over recent decades. This has resulted in warmer temperatures but the impacts of these changes on mushroom production lack documentation. We collected data on the fruiting of the highly prized matsutake mushroom (Tricholoma matsutake) in West Yunnan, China over an 11 year period from 2000 to 2010. Fruiting phenology and productivity were compared against the driving meteorological variables using Projection to Latent Structure regression. The mushrooms appeared later in the season during the observation period, which is most likely explained by rising temperatures and reduced rain during May and June. High temperature and abundant rain in August resulted in good productivity. The climate response of matsutake production results from a sequence of processes that are possibly linked with regulatory signals and resource availability. To advance the knowledge of this complex system, a holistic research approach integrating biology, ecology, genetics, physiology, and phytochemistry is needed. Our results contribute to a general model of fungal ecology, which can be used to predict the responses of fungi to global climate change.

Twenty known compounds were isolated from Viscum album L. var. meridianum Danser. As major compounds, flavanones, flavanone glycosides and triterpenenes could be chemotaxonomic markers for the genus Viscum according to our study and literatures.Highlights► This is the first report of the chemical composition of V. album var. meridianum. ► Twenty known compounds were isolated from V.album var. meridianum. ► Flavanones and triterpenenes could be chemotaxonomic markers for the genus Viscum.

Ten new ingol lathyrane-type diterpenes (1−10) and two known ingenol derivatives (11 and 12) were isolated from the aerial parts of Euphorbia royleana. The structures of 1−10 were elucidated on the basis of spectroscopic methods including 2D NMR analysis, and the structure of compound 1 was confirmed by single-crystal X-ray crystallography. Antiangiogenic effects of all compounds except for 5 were tested using a zebrafish model, with compounds 11 and 12 being active in this bioassay.

Fresh plant material is usually used for genome size estimation by flow cytometry (FCM). Lack of fresh material is cited as one of the main reasons for the dearth of studies on plants from remote locations. Genome sizes in fresh versus desiccated tissue of 16 Ophiopogoneae species and five model plant species were estimated. Our results indicated that desiccated tissue was suitable for genome size estimation; this method enables broader geographic sampling of plants when fresh tissue collection is not feasible. To be useful, after dessication the Ophiopogoneae sample should be green without brown or yellow markings; it should be stored in deep freezer at −80 °C, and the storage time should be no more than 6 months.

Stipa purpurea is widely distributed along a large precipitation gradient on the Tibetan Plateau. This implies that S. purpurea from different populations may have different responses to drought stress. To explore this we compared the morphological and physiological changes of S. purpurea seedlings cultivated from seeds from Gar County and Nagqu County after 7 and 14 days of drought stress and subsequent re-watering. The results showed that S. purpurea plants from the more arid Gar area were more tolerant to drought stress than that from Nagqu. To investigate the potential mechanisms underlying this difference, we used iTRAQ quantitative proteomics technology to analyze protein dynamics in S. purpurea samples treated with 7 days of drought stress and subsequent re-watering. The results indicated that, during the process of drought and re-watering treatments, there were differentially expressed proteins in either or both S. purpurea populations. These differential proteins were divided into 24 functional categories that were mainly associated with stress response, the antioxidant system, photosynthesis, carbohydrate metabolism, and post-translational modifications. According to these results, we concluded that the molecular basis of stronger drought resistance likely lies in the specific up-regulation or higher expression of many proteins involved in stress response, the antioxidant system, post-translational modification and osmotic regulation in S. purpurea from Gar County compared with that from Nagqu. This study improves our understanding of the intraspecific differences in drought resistance within S. purpurea populations, which helps to understand the distribution of S. purpurea along the moisture gradient, as well as the effect of climate change on this species.