The Arabidopsis F-box protein FOF2 regulates ABA-mediated seed germination and drought tolerance

The effects of temperature, light, salinity, and drought on germination of halophytes have been extensively studied. However, few studies have focused on the germination of plants that grow well in both saline and nonsaline habitats (i.e., habitat-indifferent halophytes). Here, we assess the impacts of population origin, temperature, and light on drought tolerance, as simulated with polyethylene glycol (PEG), during germination of Salsola drummondii Ulbr., a habitat-indifferent halophyte from the arid Arabian deserts. Seeds were collected from both saline and nonsaline habitats and germinated at six concentrations of PEG at three temperatures and two light regimes. An increase in the concentration of PEG resulted in a significant reduction in seed germination, especially at higher temperatures. Seeds from the nonsaline habitat attained significantly greater germination efficiency at concentrations of PEG up to –1.2 MPa, but there was no difference in germination of seeds between the two habitats at concentrations of –1.5 MPa. Seeds from the saline habitat germinated significantly faster at higher concentrations of PEG. Germination was significantly higher in darkness than in light at –1.5 MPa at the lower temperatures, but the opposite was true for the higher temperatures. Seeds from saline habitats had higher levels of dormancy and faster rates of germination at higher concentrations of PEG because of their adaptation to low osmotic potentials.

Download Full-text

Phytohormone cross-talk and antioxidant gadgets tussles osmotic stress in indigenous rice landraces during seed germination

10.21203/rs.3.rs-80159/v1 ◽

2020 ◽

Author(s):

R. Anupriya ◽

Sugitha Thankappan ◽

A. Senthil ◽

D. Rajakumar ◽

Geetha S ◽

...

Keyword(s):

Drought Stress ◽

Seed Germination ◽

Drought Tolerance ◽

Cross Talk ◽

Tamil Nadu ◽

Critical Role ◽

Hydrolytic Enzyme ◽

Rice Landraces ◽

Drought Tolerant ◽

Root And Shoot Length

Abstract Seed germination plays a critical role in determining rice productivity under drought stress. We evaluated 100 traditional rice landraces originated from different agro-ecological zones of Tamil Nadu along with drought- susceptible (IR 64) and drought- tolerant (IR 64 DRT) checks. Moisture stress was induced using PEG 6000 and screening done over a range of osmotic potentials (-) 10 bars, (-) 12.5 bars and (-)15 bars for a period of 5 d. Physio-morphological traits such as germination rate, survival per cent, root and shoot length, vigor index, RS ratio and relative water content (RWC) were assessed during early drought stress. We observed significant changes in the seed macromolecules, phytohormone levels (GA and IAA), osmolytes and antioxidant responses (catalase and superoxide dismutase) between drought stress and control treatments. Kuliyadichan registered significantly higher IAA and GA (44% and 35% respectively over drought tolerant check IR 64 DRT) at drought stress, whereas all the landraces showed an elevated catalase activity. In PC analysis, first three PCs captured 88.93% of the total variation; significant differences were detected among genotypes with respect to the studied parameters. Six traditional landraces such as Kuliyadichan, Rajalakshmi, Sabhagidhan, Nootripathu, Chandaikar and Mallikar were selected and their inherent drought tolerance was associated with metabolic responses viz., triggered hydrolytic enzyme activities, hormonal cross-talk, ROS signaling and catalase under drought stress compared to drought sensitive IR64. Hence, these genotypes can be used as potential donor candidates towards genetic improvement of drought tolerance in rice.

Download Full-text

Arabidopsis CPK6 positively regulates ABA signaling and drought tolerance through phosphorylating ABA-responsive element-binding factors

Journal of Experimental Botany ◽

10.1093/jxb/erz432 ◽

2019 ◽

Vol 71 (1) ◽

pp. 188-203 ◽

Cited By ~ 8

Author(s):

Hanfeng Zhang ◽

Daoyin Liu ◽

Bo Yang ◽

Wu-Zhen Liu ◽

Bangbang Mu ◽

...

Keyword(s):

Transcription Factors ◽

Protein Kinase ◽

Seed Germination ◽

Drought Tolerance ◽

Aba Signaling ◽

Dependent Protein Kinase ◽

Calcium Dependent ◽

Dependent Protein ◽

Responsive Element ◽

Calcium Dependent Protein Kinase

Arabidopsis calcium-dependent protein kinase CPK6 positively regulates seed germination, seedling growth, and drought tolerance via phosphorylating ABF and ABI5 transcription factors.

Download Full-text

Screening for Drought Tolerance: Evaluation of Seed Germination and Seedling Growth for Drought Resistance in Legume Plants

Journal of Agronomy and Crop Science ◽

10.1111/j.1439-037x.1996.tb00242.x ◽

1996 ◽

Vol 177 (4) ◽

pp. 245-252 ◽

Cited By ~ 16

Author(s):

S. Grzesiak ◽

W. Filek ◽

G. Skrudlik ◽

B. Niziol

Keyword(s):

Seed Germination ◽

Drought Tolerance ◽

Seedling Growth ◽

Drought Resistance ◽

Legume Plants

Download Full-text

BrEXLB1, a Brassica rapa Expansin-Like B1 Gene Is Associated with Root Development, Drought Stress Response, and Seed Germination

Genes ◽

10.3390/genes11040404 ◽

2020 ◽

Vol 11 (4) ◽

pp. 404 ◽

Cited By ~ 2

Author(s):

Muthusamy Muthusamy ◽

Joo Yeol Kim ◽

Eun Kyung Yoon ◽

Jin A. Kim ◽

Soo In Lee

Keyword(s):

Abiotic Stress ◽

Drought Stress ◽

Stress Response ◽

Seed Germination ◽

Drought Tolerance ◽

Root Growth ◽

Brassica Rapa ◽

Root Development ◽

Clubroot Disease ◽

Qrt Pcr

Expansins are structural proteins prevalent in cell walls, participate in cell growth and stress responses by interacting with internal and external signals perceived by the genetic networks of plants. Herein, we investigated the Brassica rapa expansin-like B1 (BrEXLB1) interaction with phytohormones (IAA, ABA, Ethephon, CK, GA3, SA, and JA), genes (Bra001852, Bra001958, and Bra003006), biotic (Turnip mosaic Virus (TuMV), Pectobacterium carotovorum, clubroot disease), and abiotic stress (salt, oxidative, osmotic, and drought) conditions by either cDNA microarray or qRT-PCR assays. In addition, we also unraveled the potential role of BrEXLB1 in root growth, drought stress response, and seed germination in transgenic Arabidopsis and B. rapa lines. The qRT-PCR results displayed that BrEXLB1 expression was differentially influenced by hormones, and biotic and abiotic stress conditions; upregulated by IAA, ABA, SA, ethylene, drought, salt, osmotic, and oxidative conditions; and downregulated by clubroot disease, P. carotovorum, and TuMV infections. Among the tissues, prominent expression was observed in roots indicating the possible role in root growth. The root phenotyping followed by confocal imaging of root tips in Arabidopsis lines showed that BrEXLB1 overexpression increases the size of the root elongation zone and induce primary root growth. Conversely, it reduced the seed germination rate. Further analyses with transgenic B. rapa lines overexpressing BrEXLB1 sense (OX) and antisense transcripts (OX-AS) confirmed that BrEXLB1 overexpression is positively associated with drought tolerance and photosynthesis during vegetative growth phases of B. rapa plants. Moreover, the altered expression of BrEXLB1 in transgenic lines differentially influenced the expression of predicted BrEXLB1 interacting genes like Bra001852 and Bra003006. Collectively, this study revealed that BrEXLB1 is associated with root development, drought tolerance, photosynthesis, and seed germination.

Download Full-text

Drought-Tolerant Barley: II. Root Tip characteristics in Emerging Roots

Agronomy ◽

10.3390/agronomy9050220 ◽

2019 ◽

Vol 9 (5) ◽

pp. 220 ◽

Cited By ~ 3

Author(s):

Andrea Y. Carter ◽

Michael J. Ottman ◽

Gilberto Curlango-Rivera ◽

David A. Huskey ◽

Brooke A. D’Agostini ◽

...

Keyword(s):

Seed Germination ◽

Drought Tolerance ◽

Root Hair ◽

Underlying Mechanism ◽

Cell Number ◽

Root Tip ◽

Border Cell ◽

Empirical Survey ◽

Drought Tolerant ◽

And Function

Reduced water resources are of increasingly urgent global concern. One potential strategy to address the crisis is the use of drought tolerant crops in agriculture. Barley varieties developed for reduced irrigation (“Solum” and “Solar”) use significantly less water than conventional varieties (“Cochise” and “Kopious”). The underlying mechanism of this drought tolerance is unknown but root structure and function play a key role in plant water uptake. In this study, an empirical survey compared early root development between drought tolerant and conventional varieties. Traits associated with root meristem-regulated cell division including rate of seed germination, border cell number and root cap mucilage production, and root hair emergence were quantified during root emergence. Preliminary results revealed that drought tolerant varieties exhibited faster seed germination and root hair production than conventional varieties. Border cell number and mucilage production in the drought tolerant varieties also were higher than in the conventional variety “Kopious,” but lower than in “Cochise”. Each trait, if found to be linked to the observed drought tolerance, could yield a simple, rapid, and inexpensive tool to screen for new crop varieties. Further detailed studies are needed.

Download Full-text

Seed Priming: A Feasible Strategy to Enhance Drought Tolerance in Crop Plants

International Journal of Molecular Sciences ◽

10.3390/ijms21218258 ◽

2020 ◽

Vol 21 (21) ◽

pp. 8258 ◽

Cited By ~ 1

Author(s):

Vishvanathan Marthandan ◽

Rathnavel Geetha ◽

Karunanandham Kumutha ◽

Vellaichamy Gandhimeyyan Renganathan ◽

Adhimoolam Karthikeyan ◽

...

Keyword(s):

Drought Stress ◽

Seed Germination ◽

Drought Tolerance ◽

Defense Mechanism ◽

Seed Priming ◽

Crop Productivity ◽

Crop Plants ◽

Complex Nature ◽

Efficient Manner ◽

Farming Community

Drought is a serious threat to the farming community, biasing the crop productivity in arid and semi-arid regions of the world. Drought adversely affects seed germination, plant growth, and development via non-normal physiological processes. Plants generally acclimatize to drought stress through various tolerance mechanisms, but the changes in global climate and modern agricultural systems have further worsened the crop productivity. In order to increase the production and productivity, several strategies such as the breeding of tolerant varieties and exogenous application of growth regulators, osmoprotectants, and plant mineral nutrients are followed to mitigate the effects of drought stress. Nevertheless, the complex nature of drought stress makes these strategies ineffective in benefiting the farming community. Seed priming is an alternative, low-cost, and feasible technique, which can improve drought stress tolerance through enhanced and advanced seed germination. Primed seeds can retain the memory of previous stress and enable protection against oxidative stress through earlier activation of the cellular defense mechanism, reduced imbibition time, upsurge of germination promoters, and osmotic regulation. However, a better understanding of the metabolic events during the priming treatment is needed to use this technology in a more efficient way. Interestingly, the review highlights the morphological, physiological, biochemical, and molecular responses of seed priming for enhancing the drought tolerance in crop plants. Furthermore, the challenges and opportunities associated with various priming methods are also addressed side-by-side to enable the use of this simple and cost-efficient technique in a more efficient manner.

Download Full-text