Drought and cold stress responses in orostachys spinosa L.

2018 ◽  
Vol 22 (03) ◽  
pp. 77-81
Author(s):  
Otgonsuvd B ◽  
Ouyngerel Sh ◽  
Altanzaya T

Orostachys spinosa L. is a succulent plant native to predominantly East Asia. The objective of this study was to identify physiological and morphological responses of O. spinosa L. species to cold, drought stress in laboratory conditions. Exposure of plants to a drought stress for 28 days slightly decreased the photochemical efficiency of PSII and the Fv/Fm values were 10-15% lower (0.75±0.01) compared with the control plants (0.85±0.01). For cold treatments, plants were exposed to 4°C for 60 days and for recovery transferred to normal growth conditions for 14 days. Fv/Fm photochemical efficiency of PSII can be used to monitor PSII photoinhibition. This parameter describes the efficiency of the electron transfer within PSII.The results of this study demonstrated that O. spinosa L. plants were better adapted to cold and drought conditions as they showed less visible symptoms and highest Fv/Fm levels at the long time chilling and drought stress.

2015 ◽  
Vol 15 (2) ◽  
pp. 118-122
Author(s):  
Altanzaya Tovuu ◽  
Bolortsetseg Jigmeddorj ◽  
Tumenjargal Dagvanamdal

Stipa sibirica (L) is one of important perennial grass species which belong to genus of Stipa, and family of Poaceae. It has early growth in spring and good quality for animal productivity and good adaptability in vast range of sever conditions in all over the country. Temperature and drought stress are among the two most important environmental factors influencing crop growth, development and yield processes. This study compares three stresses which as cold, drought and saline conditions. In vitro stress assays are commonly used to study the responses of plants to abiotic stress and to assess stress tolerance. Exposure of plants to a drought stress for 10 days significantly decreased the photochemical efficiency of PSII and the Fv/Fm values were almost 50% lower (0.41±0.01) compared with the control plants (0.81±0.01).During cold stress after21 days Fv/Fm decreased to 0.40 ± 0.03. The results of this study demonstrated that Stipa sibirica (L) plants were better adapted to cold conditions than the drought conditionsJournal of agricultural sciences №15 (02): 118-122, 2015


Genes ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 697
Author(s):  
Juan Mao ◽  
Wenxin Li ◽  
Jing Liu ◽  
Jianming Li

The plant glycogen synthase kinase 3 (GSK3)-like kinases are highly conserved protein serine/threonine kinases that are grouped into four subfamilies. Similar to their mammalian homologs, these kinases are constitutively active under normal growth conditions but become inactivated in response to diverse developmental and environmental signals. Since their initial discoveries in the early 1990s, many biochemical and genetic studies were performed to investigate their physiological functions in various plant species. These studies have demonstrated that the plant GSK3-like kinases are multifunctional kinases involved not only in a wide variety of plant growth and developmental processes but also in diverse plant stress responses. Here we summarize our current understanding of the versatile physiological functions of the plant GSK3-like kinases along with their confirmed and potential substrates.


2021 ◽  
Vol 12 ◽  
Author(s):  
Pajaree Sonsungsan ◽  
Pheerawat Chantanakool ◽  
Apichat Suratanee ◽  
Teerapong Buaboocha ◽  
Luca Comai ◽  
...  

Salinity is an important environmental factor causing a negative effect on rice production. To prevent salinity effects on rice yields, genetic diversity concerning salt tolerance must be evaluated. In this study, we investigated the salinity responses of rice (Oryza sativa) to determine the critical genes. The transcriptomes of ‘Luang Pratahn’ rice, a local Thai rice variety with high salt tolerance, were used as a model for analyzing and identifying the key genes responsible for salt-stress tolerance. Based on 3' Tag-Seq data from the time course of salt-stress treatment, weighted gene co-expression network analysis was used to identify key genes in gene modules. We obtained 1,386 significantly differentially expressed genes in eight modules. Among them, six modules indicated a significant correlation within 6, 12, or 48h after salt stress. Functional and pathway enrichment analysis was performed on the co-expressed genes of interesting modules to reveal which genes were mainly enriched within important functions for salt-stress responses. To identify the key genes in salt-stress responses, we considered the two-state co-expression networks, normal growth conditions, and salt stress to investigate which genes were less important in a normal situation but gained more impact under stress. We identified key genes for the response to biotic and abiotic stimuli and tolerance to salt stress. Thus, these novel genes may play important roles in salinity tolerance and serve as potential biomarkers to improve salt tolerance cultivars.


2021 ◽  
Vol 12 ◽  
Author(s):  
Nathan M. Doner ◽  
Damien Seay ◽  
Marina Mehling ◽  
Siqi Sun ◽  
Satinder K. Gidda ◽  
...  

Lipid droplets (LDs) are neutral-lipid-containing organelles found in all kingdoms of life and are coated with proteins that carry out a vast array of functions. Compared to mammals and yeast, relatively few LD proteins have been identified in plants, particularly those associated with LDs in vegetative (non-seed) cell types. Thus, to better understand the cellular roles of LDs in plants, a more comprehensive inventory and characterization of LD proteins is required. Here, we performed a proteomics analysis of LDs isolated from drought-stressed Arabidopsis leaves and identified EARLY RESPONSIVE TO DEHYDRATION 7 (ERD7) as a putative LD protein. mCherry-tagged ERD7 localized to both LDs and the cytosol when ectopically expressed in plant cells, and the protein’s C-terminal senescence domain (SD) was both necessary and sufficient for LD targeting. Phylogenetic analysis revealed that ERD7 belongs to a six-member family in Arabidopsis that, along with homologs in other plant species, is separated into two distinct subfamilies. Notably, the SDs of proteins from each subfamily conferred targeting to either LDs or mitochondria. Further, the SD from the ERD7 homolog in humans, spartin, localized to LDs in plant cells, similar to its localization in mammals; although, in mammalian cells, spartin also conditionally localizes to other subcellular compartments, including mitochondria. Disruption of ERD7 gene expression in Arabidopsis revealed no obvious changes in LD numbers or morphology under normal growth conditions, although this does not preclude a role for ERD7 in stress-induced LD dynamics. Consistent with this possibility, a yeast two-hybrid screen using ERD7 as bait identified numerous proteins involved in stress responses, including some that have been identified in other LD proteomes. Collectively, these observations provide new insight to ERD7 and the SD-containing family of proteins in plants and suggest that ERD7 may be involved in functional aspects of plant stress response that also include localization to the LD surface.


2021 ◽  
Author(s):  
Hongjie Li ◽  
Mei Yang ◽  
Chengfeng Zhao ◽  
Yifan Wang ◽  
Renhe Zhang

Abstract Background: Drought stress seriously limits the seedling growth and yield of maize. Despite previous studies on drought resistance mechanisms by which maize cope with water deficient, the link between physiological and molecular variations are largely unknown. To reveal the complex regulatory mechanisms, comparative physiology and proteomic analyses were conducted to investigate the stress responses of two maize cultivars with contrasting tolerance to drought stress. Results: Physiological results showed that SD609 (drought-tolerant) maintains higher photochemical efficiency by enhancing CEF (cyclic electron flow) protective mechanism and antioxidative enzymes activities. Proteomics analysis revealed a total of 198 and 102 proteins were differentially expressed in SD609 and SD902, respectively. Further enrichment analysis indicated that drought-tolerant ‘SD609’ increased the expression of proteins related to photosynthesis, antioxidants/detoxifying enzymes, molecular chaperones and metabolic enzymes. The up-regulation proteins related to PSII repair and photoprotection mechanisms resulted in more efficient photochemical capacity in tolerant variety under moderate drought. However, the drought-sensitive ‘SD902’ only induced molecular chaperones and sucrose synthesis pathways, and failed to protect the impaired photosystem. Further analysis indicated that proteins related to the electron transport chain, redox homeostasis and heat shock proteins (HSPs) could be important in protecting plants from drought stress. Conclusions: Our experiments explored the mechanism of drought tolerance, and obtained detailed information about the interconnection of physiological research and protein research. In summary, our findings could provide new clues into further understanding of drought tolerance mechanisms in maize.


HortScience ◽  
2005 ◽  
Vol 40 (4) ◽  
pp. 1036E-1037
Author(s):  
Mohamed Tawfik ◽  
Alejandra Ferenczi ◽  
Daniel Enter ◽  
Rebecca Grumet

Abiotic stresses (e.g., salinity, drought, cold, oxidative stress) can be major factors limiting plant productivity worldwide. We sought to increase abiotic stress resistance in cucumber by expressing the A. thaliana transcription factors CBF1and CBF3, which regulate genes responsible for enhanced dehydration-stress resistance in Arabidopsis. Our previous studies in the greenhouse and field demonstrated increased salinity tolerance in CBF-expressing cucumber lines. In the current studies, we tested response of CBF-cucumber plants to drought, chilling, and oxidative stresses. Transgenic cucumber plants subjected to drought stress in the greenhouse showed elevated levels of the stress-inducible compatible solute, proline, compared to the nontransgenic controls. Preliminary results also indicate greater photochemical efficiency in CBF-expressing plants under drought stress conditions compared to the nontransgenic controls. Under nonstressed conditions, there were no significant differences in growth between the transgenic and the nontransgenic cucumber plants; however, after a cycle of drought stress, CBF-cucumber lines had less growth reduction compared to the nontransgenic counterparts. The advantage in growth was less pronounced after a second cycle of drought. We also evaluated the transgenic cucumber plants under chilling conditions (i.e., low, nonfreezing temperatures within the 0 to 12 °C range). Based on plant height and cotyledon and leaf damage measurements, transgenic cucumber seedlings did not show chilling tolerance compared to the wild-type control. The response of transgenic CBF-cucumber plants to oxidative stress using methyl viologen is also being evaluated.


2020 ◽  
Author(s):  
Kai Liu ◽  
Mingjuan Li ◽  
Bin Zhang ◽  
Yanchun Cui ◽  
Xuming Yin ◽  
...  

Abstract BackgroundGrain yield is a polygenic trait influenced by environmental and genetic interactions at all growth stages of the cereal plant. However, the molecular mechanisms responsible for coordinating the trade-off or cross-talk between these traits remain elusive.ResultsWe characterized the hitherto unknown function of four STRESS_tolerance and GRAIN_LENGTH (OsSGL) Poaceae ortholog genes, all encoding DUF1645 domain-containing proteins, in simultaneous regulation of grain length, grain weight, and drought stress-tolerance in rice. In normal growth conditions, the four ortholog genes were mainly expressed in the developing roots and panicles of the corresponding species. Over-expressing or heterologous high-level expressing Poaceae OsSGL ortholog genes conferred remarkably increased grain length, weight, and seed setting percentage, as well as significantly improved drought-stress tolerance in transgenic rice. Microscopical analysis also showed that the transgene expression promoted cell division and development. RNA-seq and qRT-PCR analyses revealed 73.8% (18,711) overlapped DEGs in all transgenic plants. Moreover, GO and KEGG analyses of different comparisons revealed that the key DEGs participating in drought stress-response belonged to hormone (especially auxin and cytokinin) pathways, and signaling processes were apparently affected in the young panicles. ConclusionTogether, these results suggest the four OsSGL orthologs perform a conserved function in regulating stress-tolerance and cell growth by acting via a hormone biosynthesis and signaling pathway. It may also induce a strategy for tailor-made crop yield improvement.


2019 ◽  
Author(s):  
Chao Cheng ◽  
Shutong Hu ◽  
Yun Han ◽  
Di Xia ◽  
Bang-Lian Huang ◽  
...  

Abstract Using RACE PCR, full length WRI1-like gene was amplified from yellow nutsedge. Conserved domain and phylogenetic analyses suggested it as WRI3/4-like gene. Tissue-specific expression data showed the highest expression in leaves, followed by roots while the lowest expression was detected in tuber. Transgenic Arabidopsis plants expressing nutsedge WRI3/4-like gene showed significantly improved tolerance to both PEG-simulated drought stress and real dehydration, compared with the wild type (WT). Under normal growth conditions, the expressions of key fatty acid biosynthesis genes was not significantly different between WT and transgenic lines, while the expressions of genes involved in cuticular wax biosynthesis was significantly higher in transgenic lines compared with the WT. The PEG-simulated drought stress did not induce any significant change in the expression of fatty acid and wax biosynthesis genes in WT plants, while the expression of fatty acid and wax biosynthesis genes was significantly increased in transgenic lines compared with WT as well as unstressed transgenic control. The expression of TAG1, the gene involved in triacylglycerol (TAG) accumulation, was significantly lower in the transgenic lines than that in the WT in normal growth conditions. Drought stress slightly decreased the expression of TAG1 in the WT, but significantly lowered it in transgenic lines compared with its unstressed transgenic control and WT. Consistent with gene expression data, the cuticular wax content in Arabidopsis leaves was significantly higher in the transgenic lines than in the WT, while the oil content was not significantly different. Our results indicated that WRI3/4-like gene from Cyperus esculentus improves drought tolerance in Arabidopsis probably by promoting cuticular wax biosynthesis and, hence, could be a valuable target for improving drought tolerance in crops through recombinant DNA technology.


Genes ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 1119
Author(s):  
Basmah M. Alharbi ◽  
Awatif Mahfouz Abdulmajeed ◽  
Heba Hassan

To assess the effect of triacontanol (TRIA) on rice plants grown under normal or drought conditions, rice seeds were presoaked in TRIA (35 ppm) for two hours. After 20 days of sowing, rice seedlings developed from TRIA-treated or untreated seeds were subjected to drought stress. After 10 days of plant exposure to drought stress, data of major growth attributes and the content of photosynthetic pigments were recorded. Moreover, the effect of drought stress on stomatal conductance and the photochemical efficiency of PSII (Fv/Fm) were followed. The data obtained indicated that the species of rice (Oryza sativa L.) cultivar Giza 177 under investigation was sensitive to drought stress where there were significant decreases in the fresh and dry weights of shoots and roots and in stomatal conductance, as well as in the content of chlorophyll a, chlorophyll b, and carotenoids. Seed priming with TRIA enhanced both growth and acquired plant tolerance to drought stress. Thus, TRIA via the enhancement of stomatal conductance through the regulation of stomatal closure, the rate of water loss, ABA metabolism, the accumulation of osmolytes, and the regulation of aquaporins genes improved the water status of plants grown under water scarcity. Moreover, TRIA via increasing the content of free amino acids and sugars under drought stress may increase the chance of plant tissues to retain more water under scarcity conditions.


2015 ◽  
Vol 140 (1) ◽  
pp. 94-101 ◽  
Author(s):  
Vijaya Shukla ◽  
Yingmei Ma ◽  
Emily Merewitz

Polyamines (PAs) such as spermidine (Spd), spermine (Spm), and putrescine are involved in various biological functions including abiotic stress response. Whether PAs play an important role in cool-season turfgrass tolerance of drought stress is not well investigated. We have conducted a series of growth chamber (GC) studies including one hydroponic and two soil-based GC studies with creeping bentgrass (Agrostis stolonifera) ‘Penncross’ and ‘Penn-G2’ to determine whether exogenous application of PAs may affect plant growth and stress tolerance. Application of relatively low concentrations of Spd (500 or 750 μM) or Spm (500 μM) promoted tillering rates under optimal growth conditions in hydroponics. The same levels of PA treatments moderated the damages associated with drought stress in the soil-based GC studies. The most notable differences in drought response associated with PA treatment were increased membrane health. This was observed as greater photochemical efficiency, higher quantum yield, less electrolyte leakage, and less lipid peroxidation (malondialdehyde content) in PA-treated plants compared with control plants. The relatively low level of exogenous PAs used in this study did not have a major effect on plant water relations under drought stress. Canopy temperatures and soil moisture content were unaffected by any PA treatment; however, on some days during early drought stress, relative water content was significantly higher in PA-treated plants compared with controls. PA could play a major role in protecting photosynthetic and cellular membranes during drought stress of creeping bentgrass.


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