PEG-induced Drought Stress Research Articles

Bioprospecting Nigeria tomato cultivars against Fusarium oxysporum lycopersici under polyethylene glycol-induced drought stress

Among the vegetables, tomato is one of the economically important vegetables even at the global level. The nutritional and health benefits of tomato are so numerous to the extent that it has gained so much value in Africa due to its low-cost cultivation and contribution to livelihoods. However, Fusarium oxysporum lycopersici (FOL) and drought have been identified as potential threats to tomato production in Nigeria. To manage these challenges, one of the approaches is to identify Nigerian tomato cultivars that can exhibit resistance to FOL and drought. This study therefore investigates four Nigeria tomato cultivars; NGB00714, NGB00715, NGB00725 and NGB00740 to ascertain their resistance attributes to FOL and drought. Prior to their evaluation, Petri - dish seed germination bioassay was used in-vitro to assess the germination potentials of the tomato seeds. NGB00725 had the best germination, followed by NGB00714 and NGB00740 while the least was NGB00715. Using the Petri - dish in-vitro blotter technique, each tomato seed cultivar was separately exposed to FOL spores and FOL metabolites under drought stress induced by polyethyleneglycol (PEG-6000). Cultivar NGB00725, followed by NGB00740 exhibited resistance to FOL under PEG-induced drought stress based on their seed germination potentials. Bioprospecting resistant Nigeria tomato cultivars in this study is an indication of sustainable production of tomatoes in Nigeria against FOL under drought stress.

Enhancing drought resistance in Pinus tabuliformis seedlings through root symbiotic fungi inoculation.

Drought constitutes a major abiotic stress factor adversely affecting plant growth and productivity. Plant-microbe symbiotic associations have evolved regulatory mechanisms to adapt to environmental stress conditions. However, the interactive effects of different fungi on host growth and stress tolerance under drought conditions remain unclear. This study explored the effects of varying polyethylene glycol (PEG-6000) concentrations (0%, 15%, 25%, and 35%) on the growth and physiological responses of two ectomycorrhizal fungi (Suillus granulatus (Sg) and Pisolithus tinctorius (Pt)) and two dark septate endophytes (Pleotrichocladium opacum (Po) and Pseudopyrenochaeta sp. (Ps)) isolated from the root system of Pinus tabuliformis. Specifically, the study aimed to evaluate six inoculation treatments, including no inoculation (CK), single inoculations with Sg, Pt, Po, Ps, and a mixed inoculation (Sg: Pt : Po: Ps = 1:1:1:1), on the growth and physiological characteristics of P. tabuliformis seedlings under different water regimes: well-watered at 70% ± 5%, light drought at 50% ± 5%, and severe drought at 30% ± 5% of the maximum field water holding capacity. All four fungi exhibited the capacity to cope with drought stress by enhancing antioxidant activities and regulating osmotic balance. Upon successful root colonization, they increased plant height, shoot biomass, root biomass, total biomass, and mycorrhizal growth response in P. tabuliformis seedlings. Under drought stress conditions, fungal inoculation improved seedling drought resistance by increasing superoxide dismutase and catalase activities, free proline and soluble protein contents, and promoting nitrogen and phosphorus uptake. Notably, mixed inoculation treatments significantly enhanced antioxidant capacity, osmotic adjustment, and nutrient acquisition abilities, leading to superior growth promotion effects under drought stress compared to single inoculation treatments. All four fungi tolerated PEG-induced drought stress, with increased antioxidant enzyme activities and osmotic adjustment substances and they promoted the growth and enhanced drought resistance of P. tabuliformis seedlings.

Transcriptome Profiling and Weighted Gene Correlation Network Analysis Reveal Hub Genes and Pathways Involved in the Response to Polyethylene-Glycol-Induced Drought Stress of Two Citrus Rootstocks.

Agriculture faces the dual challenge of increasing food production and safeguarding the environment. Climate change exacerbates this challenge, reducing crop yield and biomass due to drought stress, especially in semi-arid regions where Citrus plants are cultivated. Understanding the molecular mechanisms underlying drought tolerance in Citrus is crucial for developing adaptive strategies. Plants of two citrus rootstocks, Carrizo Citrange and Bitters (C22), were grown in aerated half-strength Hoagland's nutrient solution. Post-acclimation, the plants were exposed to a solution containing 0% (control) or 15% PEG-8000 for 10 days. Leaf malonyl dialdehyde (MDA) and hydrogen peroxide (H2O2) content were measured to assess the reached oxidative stress level. Total RNA was extracted, sequenced, and de novo-assembled. Weighted Gene Correlation Network Analysis (WGCNA) was conducted to examine the relationship between gene expression patterns and the levels of MDA and H2O2 used as oxidative stress indicators. Plant visual inspection and MDA and H2O2 contents clearly indicate that Bitters is more tolerant than Carrizo towards PEG-induced drought stress. RNA-Seq analysis revealed a significantly higher number of differentially expressed genes (DEGs) in Carrizo (6092) than in Bitters (320), with most being associated with drought sensing, ROS scavenging, osmolyte biosynthesis, and cell wall metabolism. Moreover, the WGCNA identified transcription factors significantly correlated with MDA and H2O2 levels, thus providing insights into drought-coping strategies and offering candidate genes for enhancing citrus drought tolerance.

Genome-wide analysis of MYB transcription factor family and AsMYB1R subfamily contribution to ROS homeostasis regulation in Avena sativa under PEG-induced drought stress

BackgroundThe myeloblastosis (MYB) transcription factor (TF) family is one of the largest and most important TF families in plants, playing an important role in a life cycle and abiotic stress.ResultsIn this study, 268 Avena sativa MYB (AsMYB) TFs from Avena sativa were identified and named according to their order of location on the chromosomes, respectively. Phylogenetic analysis of the AsMYB and Arabidopsis MYB proteins were performed to determine their homology, the AsMYB1R proteins were classified into 5 subgroups, and the AsMYB2R proteins were classified into 34 subgroups. The conserved domains and gene structure were highly conserved among the subgroups. Eight differentially expressed AsMYB genes were screened in the transcriptome of transcriptional data and validated through RT-qPCR. Three genes in AsMYB2R subgroup, which are related to the shortened growth period, stomatal closure, and nutrient and water transport by PEG-induced drought stress, were investigated in more details. The AsMYB1R subgroup genes LHY and REV 1, together with GST, regulate ROS homeostasis to ensure ROS signal transduction and scavenge excess ROS to avoid oxidative damage.ConclusionThe results of this study confirmed that the AsMYB TFs family is involved in the homeostatic regulation of ROS under drought stress. This lays the foundation for further investigating the involvement of the AsMYB TFs family in regulating A. sativa drought response mechanisms.

On the “priming” steps: initial results on the effect of PEG-induced drought stress upon the oxidative status and related gene expression in Citrus rootstocks

On the “priming” steps: initial results on the effect of PEG-induced drought stress upon the oxidative status and related gene expression in <i>Citrus</i> rootstocks

GA3 and BAP phytohormone seed priming enhances germination and PEG induced drought stress tolerance in soybean by triggering the expression of osmolytes, antioxidant enzymes and related genes at the early seedling growth stages

Drought stress strongly affects seed germination and seedling development during the early stages of plant growth in soybean (Glycine max L.). Seed priming with phytohormone (PH) is known to regulate various physiological and biochemical processes that govern plant growth and yield under optimal and stress conditions. In the present study, the effects of seed priming with Gibberellic acid (GA3) (0.28 mM), 6-Benzyl aminopurine (BAP) (20 mM) and Methyl Jasmonate (MJ) (2.5 mM) was studied during germination and at early seedling growth stages in JS-335 (drought sensitive) and MAUS-71 (moderately drought tolerant) soybean varieties under PFG induced drought stress conditions. The seed priming effects were studied in terms of germination percentage and rate (Timson Index), accumulation of osmolytes (proline and glycine betaine), antioxidant enzymes activity (superoxide dismutase (SOD), ascorbate peroxidase (APX) and catalase (CAT)), and the relative expression of genes viz., Cu/Zn-superoxide dismutase copper chaperone (SOD-CCS) , iron-superoxide dismutase (SODB2) , betaine aldehyde dehydrogenase (BADH2) and dehydration-responsive element binding protein (DREB2A). The germination percentage of non-primed soybean seeds decreased under drought stress but significantly increased upon GA3 and BAP priming. Interestingly, seed priming with MJ completely inhibited the germination in both the varieties. GA3 and BAP seed priming increased proline and glycine betaine accumulation under PEG induced drought stress in both the soybean varieties. The results showed that the activities of SOD, APX and CAT were significantly enhanced in the leaves of seedlings raised from GA3 and BAP-primed seeds, as compared to the non-primed seeds under the drought stress conditions. Isozyme profiling of SOD and APX revealed that the GA3 and BAP seed priming treatments enhanced the drought-inducible expression of SOD isozymes rather than inducing novel isoforms. In case of APX isozymes, GA3 seed priming appears to preserve APX isozyme diversity in both varieties, and BAP seed priming elevated the expression of APX isoforms in both soybean varieties under the drought conditions. In response to the drought stress, relative expression of the genes associated with superoxide dismutase and glycine betaine viz., SOD CCS, SODB2, BADH2 and DREB2A was markedly upregulated in the leaves of seedlings raised from the GA3 and BAP primed seeds in both the soybean varieties. The global correlation analysis designated that the osmolyte Proline, antioxidant enzyme APX and CAT, and SOD CCS, SODB2, BADH2 and DREB2A genes were potent regulator for drought stress tolerance mechanism in soybean. This study illuminates the intricate interplay of GA3 and BAP hormonal seed priming during the germination and early seedling stages in soybean plants under the drought stress. This finding emphasizes the critical consideration of genotype specific reactions to the hormonal seed priming under PEG induced drought stress conditions.

Screening of lentil genotypes during germination and early growth stages under PEG-induced drought stress

Screening of lentil genotypes during germination and early growth stages under PEG-induced drought stress

Variability of Root and Shoot Traits under PEG-Induced Drought Stress at an Early Vegetative Growth Stage of Soybean

Variability of Root and Shoot Traits under PEG-Induced Drought Stress at an Early Vegetative Growth Stage of Soybean

Exogenous Streptomyces spp. enhance the drought resistance of naked oat (Avena nuda) seedlings by augmenting both the osmoregulation mechanisms and antioxidant capacities.

Drought is a major obstacle to the development of naked oat industry. This work investigated mechanisms by which exogenous Streptomyces albidoflavus T4 and Streptomyces rochei D74 improved drought tolerance in naked oat (Avena nuda ) seedlings. Results showed that in the seed germination experiment, germination rate, radicle and hypocotyl length of naked oat seeds treated with the fermentation filtrate of T4 or D74 under PEG induced drought stress increased significantly. In the hydroponic experiment, the shoot and root dry weights of oat seedlings increased significantly when treated with the T4 or D74 fermentation filtrate under the 15% PEG induced drought stress (S15). Simultaneously, the T4 treatment also significantly increased the surface area, volume, the number of tips and the root activity of oat seedlings. Both T4 and D74 treatments elicited significant increases in proline and soluble sugar contents, as well as the catalase and peroxidase activities in oat seedlings. The results of comprehensive drought resistance capacity (CDRC) calculation of oat plants showed that the drought resistance of oat seedlings under the T4 treatment was better than that under the D74 treatment, and the effect was better under higher drought stress (S15). Findings of this study may provide a novel and effective approach for enhancing plant defenses against drought stress.

Genome-wide identification and expression analysis of TIFY genes under MeJA, cold and PEG-induced drought stress treatment in Dendrobium huoshanense.

The online version contains supplementary material available at 10.1007/s12298-024-01442-9.

Peribacillus frigoritolerans T7-IITJ, a potential biofertilizer, induces plant growth-promoting genes of Arabidopsis thaliana.

This study aimed to isolate plant growth and drought tolerance-promoting bacteria from the nutrient-poor rhizosphere soil of Thar desert plants and unravel their molecular mechanisms of plant growth promotion. Among our rhizobacterial isolates, Enterobacter cloacae C1P-IITJ, Kalamiella piersonii J4-IITJ, and Peribacillus frigoritolerans T7-IITJ, significantly enhanced root and shoot growth (4-5-fold) in Arabidopsis thaliana under PEG-induced drought stress. Whole genome sequencing and biochemical analyses of the non-pathogenic bacterium T7-IITJ revealed its plant growth-promoting traits, viz., solubilization of phosphate (40-73µg/ml), iron (24±0.58mm halo on chrome azurol S media), and nitrate (1.58±0.01µg/ml nitrite), along with production of exopolysaccharides (125±20µg/ml) and auxin-like compounds (42.6±0.05µg/ml). Transcriptome analysis of A. thaliana inoculated with T7-IITJ and exposure to drought revealed the induction of 445 plant genes (log2fold-change>1, FDR<0.05) for photosynthesis, auxin and jasmonate signalling, nutrient uptake, redox homeostasis, and secondary metabolite biosynthesis pathways related to beneficial bacteria-plant interaction, but repression of 503 genes (log2fold-change < -1) including many stress-responsive genes. T7-IITJ enhanced proline 2.5-fold, chlorophyll 2.5-2.8-fold, iron 2-fold, phosphate 1.6-fold, and nitrogen 4-fold, and reduced reactive oxygen species 2-4.7-fold in plant tissues under drought. T7-IITJ also improved the germination and seedling growth of Tephrosia purpurea, Triticum aestivum, and Setaria italica under drought and inhibited the growth of two plant pathogenic fungi, Fusarium oxysporum, and Rhizoctonia solani. P. frigoritolerans T7-IITJ is a potent biofertilizer that regulates plant genes to promote growth and drought tolerance.

The impact of PEG-induced drought stress on early vigour traits of bread wheat

ABSTRACT A total of 11 genotypes from the collection of 101 bread wheat genotypes, with desirable traits in terms of increased tolerance to drought, were chosen for parents and eight crosses were performed. Number of seminal roots (NSR), total root length (TRL), root dry mass (RDM), number of shoots per plant (NS), main shoot length (MSL), shoot dry mass (SDM), number of leaves per plant (NL), leaf area per plant (LA), leaf dry mass (LDM), aboveground dry mass (ADM), SDM/LDM, RDM/ADM were analysed at the boot stage (Z45). The F1 progeny had on average higher mean values (P < 0.001) than parents for four traits: RDM, NS, LA and RDM/ADM. The highest broad sense heritability values were determined for RDM (97.6%) and NSR (93.9%). Factor analysis indicated that a large root system, higher RDM and TRL are associated with higher NS, NL, LA and LDM. For Euclid x CHI-4 and WWBMC2 x Ingenio combinations the highest heterosis values were observed for TRL (34.1%) and SDM (23.7%), for RDM (28.6%) and LA (26.8%), respectively. PEG-induced drought stress in the seedling stage, in most of the new germplasm, caused an increased redistribution of dry matter in the root compared to the stem.

Antioxidant Defense System and Physiological Insights to Drought Stress in Urtica dioica L.

Urtica dioicais an endemic perennial plant of rocky habitat of Western Black Sea region of Turkey. To understand drought responses and tolerance mechanism of Seseli resinosum Freyn &amp; Sint., relative water content (RWC), chlorophyll fluorescence, proline accumulation, lipid peroxidation (TBARS), hydrogen peroxide (H2O2) content and changes in antioxidant enzymes were assayed in polyethylene glycol (PEG) 6000 (5, 10 and 15%) induced drought stress in the present study. Leaf RWC maintained unchanged, while chlorophyll fluorescence reduced with high level of PEG (15%). Additionally, H2O2 and proline accumulation were determined with the increase of PEG application, but no increase in the amount of TBARS was determined. Moreover, the increment in H2O2 content under drought was accompanied by increased in glutathione reductase, catalase and superoxide dismutase activities. On the other hand, PEG-induced drought stress caused a reduction in peroxidase and ascorbate peroxidase activities. These results suggest that endemic Urtica dioica plant have an efficient drought tolerance, as displayed by enhanced antioxidant enzyme activities with maintaining water status under drought conditions. In this study, important information about physiological and antioxidative responses of endemic Urtica dioica was revealed for the first time.

Alleviating Impact of PEG Induced Drought Stress on Maize Seed Germination and Vigour with Effective Seed Priming Agents

Background: Drought stress poses a significant challenge to agricultural productivity, particularly in regions with limited water availability. Maize, a staple crop worldwide, is highly susceptible to drought stress, leading to reduced seed germination, stunted growth and ultimately diminished yields. Addressing this issue, in this study various phytohormones and polyamines were used as priming agents for seeds to evaluate its performance to mitigate drought stress in maize seed germination and vigour. It plays crucial roles in regulating plant growth and development, as well as responses to various environmental stresses, including drought. These hormones modulate physiological and biochemical processes, leading to adaptive changes that helps maize plants to cope with water scarcity. Methods: The experiment was conducted by exposing maize seeds primed with different phytohormones and polyamines in optimum along with non primed seeds (control) to various levels of PEG concentration ranging from -0.2 MPa to -1.0 MPa for creating drought stress. Primed seeds subjected to a germination test. The seedling growth parameters and seed vigour were evaluated to analyse better performing seed priming treatment to mitigate drought stress. Result: From the experiment it is concluded that increase in concentration of PEG (from -0.2 Mpa to -1.0 MPa) decreased the seed germination and seed vigour traits in maize. Among seed priming treatments, seeds primed with melatonin 150 µM showed greater performance seedling vigour and its related traits even under water deficit stress condition. In conclusion, seed priming with melatonin exhibited superior efficacy in mitigating drought stress in maize. This finding highlights the potential of melatonin as a promising seed priming agent for enhancing drought tolerance in maize seeds. As seed priming is simple, easy and cost effective method, farmers can use this technology as one of their practice to eliminate the effect of drought stress in maize crop.

Effect of PEG induced drought stress on Genetic diversity using SDS-PAGE and ISSR markers for Egyptian barley varieties

Effect of PEG induced drought stress on Genetic diversity using SDS-PAGE and ISSR markers for Egyptian barley varieties

Genome and transcriptome reveal lithophilic adaptation of Cladophialophora brunneola, a new rock-inhabiting fungus

ABSTRACT Rock-inhabiting fungi (RIF) are slow-growing microorganisms that inhabit rocks and exhibit exceptional stress tolerance owing to their thick melanised cell walls. This study reports the identification of a novel rock-inhabiting fungus, Cladophialophora brunneola sp. nov. which was isolated from a karst landform in Guizhou, China, using a combination of morphological and phylogenetic analyses. The genome of C. brunneola was sequenced and assembled, with a total size of approximately 33.8 Mb, encoding 14,168 proteins and yielding an N50 length of 1.88 Mb. C. brunneola possessed a larger proportion of species-specific genes, and phylogenomic analysis positioned it in an early diverged lineage within Chaetothyriales. In comparison to non-RIF, C. brunneola displayed reduction in carbohydrate-active enzyme families (CAZymes) and secondary metabolite biosynthetic gene clusters (BGCs). Transcriptome analysis conducted under PEG-induced drought stress revealed elevated expression levels of genes associated with melanin synthesis pathways, cell wall biosynthesis, and lipid metabolism. This study contributes to our understanding of the genomic evolution and polyextremotolerance exhibited by rock-inhabiting fungi.

DUF4057 containing express-protein negatively regulates the drought responses in rice

The current global climatic conditions project drought as a severe form of abiotic stress that directly impacts the agricultural productivity of economically important crops. In this study, we conducted a functional characterization of a drought-responsive express-protein (OsEP) that contains the DUF-4057 superfamily domain. In silico analysis revealed differential expression of the OsEP gene in two drought-responsive rice varieties with contrasting characteristics (Heena, drought-tolerant, and Kiran, drought-sensitive). According to phylogenetic analysis, OsEP showed a high amino acid identity with the protein of Panicum hallii and Zizania palustris. Following treatment with 20% PEG, quantitative real-time PCR demonstrated an increased abundance of OsEP gene transcripts. The OsEP gene exhibited the highest expression levels in the gynoecium and roots of the rice plant. Notably, rice lines over-expressing OsEP were found to be sensitive to PEG-induced drought stress, whereas knockdown lines exhibited improved root architecture and lignification of root cells, enabling them to withstand severe water deficit conditions. Furthermore, drought stress compromised the growth parameters and grain yield of OsEP over-expressing lines compared to knock-down lines. Increased activity of antioxidant enzymes such as CAT (catalase), APX (Ascorbate peroxidase), and SOD (Superoxide Dismutase) was observed in knock-down lines compared to both over-expressing lines and wild-type plants. Additionally, knock-down lines exhibited decreased levels of membrane stability marker (MDA) and electrolyte leakage, along with elevated proline content. Important regulatory genes such as OsHsfC1b, OsbZIP81, and OsNCED, positively impacted by osmotic/drought stress, exhibit variable expression in over-expressing and knock-down lines. These findings suggest that down-regulation of the OsEP gene modulates the genomic architecture of knock-down lines, allowing them to maintain cellular homeostasis by regulating enzymatic activity. Our results indicate that the OsEP gene is a negative regulator of drought response. Moreover, GA-JA (Gibberellic Acid-Jasmonic Acid) cross-talk is involved in the down-regulation of stress-related phenomena in over-expressing lines. Overall, this study sheds light on the crucial role of the DUF4057 superfamily gene in drought response and provides insights into its potential regulatory mechanism.

RNA-seq provides insights into potato deubiquitinase responses to drought stress in seedling stage.

Ubiquitination is a specific protein degradation and reversible post-translational modification process that can be reversed by deubiquitinase (DUBs). DUBs can hydrolyze and release ubiquitin in the substrate protein so that the substrate can avoid degradation or change its activity, and it has an impact on plant growth and development, cell cycle, abiotic stress response, and other biological processes. Transcript sequences of potato varieties "DM1-3", "Atlantic" and "Cooperation-88" downloaded from Potato Genome Resources were used for genome-wide identification of the DUB gene family using Hidden Markov Models and verified in the NCBI CD-Search tool. The characteristics of DUB genes from different potato varieties were analyzed including subcellular localization, gene structural motifs, phylogenetic tree, and sequence homology. Polyethylene glycol 6000 (PEG6000) induced drought stress transcriptome analysis was performed on the "Atlantic", and differentially expressed genes were screened, with emphasis on the characterization of deubiquitinase. DUB genes have a complex gene structure, often with a large number of exons and alternative splicing. Their promoters contain abundant abiotic stress-responsive elements, such as 425 MYC, 325 ABRE, and 320 MYB. There are also a large number of orthologous genes in the DUBs of the three potato varieties, and these genes are often clustered in similar regions on the genome. We performed transcriptome sequencing of the potato under PEG-induced drought stress and analyzed it for the first time using the Atlantic as a reference genome. We identified a total of 6067 down-regulated differentially expressed genes (DEGs) and 4950 up-regulated DEGs under PEG-induced drought stress. We screened the expression of DUBs and observed that 120 DUBs were up-regulated where most of them functioned in the nucleus, and the interacting proteins of DUBs were also localized in the nucleus. We have comprehensively identified and analyzed potato DUBs, and the accurately aligned transcriptome data which will further deepen the understanding of DUBs involved in the regulation of osmotic stress.

Genetic Studies for Yield Components and Screening for Drought Tolerance at Seedling Stage of Maize (Zea mays L.) Genotypes

A field experiment involving 30 genotypes of maize was carried out under the field condition during Rabi 2021-2022 to study the association of yield contributing characters among themselves along with direct and indirect effects on grain yield per plant and identify the genotypes which are highly efficient with respect to different PEG induced drought stress. The results of the study revealed that plant height, leaf length, ear height, number of grain rows per cob, number of grains per row, cob girth, cob weight, biological yield per plant, 100 grains weight and harvest index showed positive significant association with grain yield per plant both at genotypic and phenotypic levels. Plant height showed positive significant association with leaf length, ear height, number of grain rows per cob, cob girth, cob weight, 100 grains weight, biological yield per plant and grain yield per plant. Days to fifty per cent silking, anthesis to silking interval, days to maturity, number of grain rows per cob exhibited negative direct effect while number of cobs per plant, leaf width, cob length, cob weight, biological yield per plant and harvest index exhibited positive direct effect on grain yield per plant. For improvement of seed yield, attention should be given for traits such as cob weight, biological yield per plant and harvest index which showed high positive correlation coefficients with a considerable direct and indirect effect on grain yield. MGC-192 has shown high root length, shoot length, seedling length, seedling dry weight, seedling vigour index 1, seedling vigour index II, germination percentage and MGW-392 has shown high relative water content under PEG induced stress condition, hence this genotype is suggested for future selection.

Genome-wide analysis of the SMXL gene family in common bean and identification of karrikin-responsive PvSMXL2 as a negative regulator of PEG-induced drought stress

Common bean (Phaseolus vulgaris L.) is a major legume crop worldwide, but its growth and development frequently face challenges due to abiotic stresses, particularly drought. Proper supplement of copper could mitigate the adverse effects of drought, but excessive accumulation of this metal in plants can be harmful. The suppressor of MAX2 1-like (SMXL) gene family, which plays important roles in various plant processes, including stress responses, remains poorly understood in common bean. In this study, we identified nine orthologues of SMXL genes in common bean, which are located on six chromosomes and classified into four subgroups. Basic molecular properties, including theoretical isoelectric point (PI), molecular weight (MW), grand average of hydropathicity (GVIO), gene structure, and conserved motifs were characterized, and numerous cis-elements in promoters were predicted. The expression patterns of PvSMXL genes were found to be distinct under 10% polyethylene glycol (PEG)-induced drought stress and 200 μM Cu treatments. Most PvSMXLs showed reduced expression in response to Cu treatment, whereas nearly half PvSMXLs exhibited inducible expression under drought stress. PvSMXL2, which exhibited a rapid response to karrikin 1 (KAR1), an active form of the plant growth regulators newly found in the smoke of burning plant material, was down-regulated by both PEG-induced drought and Cu stresses. Transient silencing of PvSMXL2 resulted in enhanced drought stress tolerance without conferring Cu tolerance. These findings provide valuable insights into the functions of SMXL genes in common bean under abiotic stress conditions.