Plant growth-promoting rhizobacteria (PGPR) play a vital role in sustainable agriculture by enhancing plant growth and improving tolerance to both abiotic and biotic stresses. In this study, we investigated the rhizosphere of Argania spinosa to identify bacterial strains with potential PGPR and biocontrol properties. Bacteria were isolated from rhizospheric soil and screened for their ability to produce indole-3-acetic acid (IAA), generate ammonia, solubilize phosphate, and inhibit fungal growth in vitro. Their plant growth-promoting effects were evaluated on Argania spinosa and tomato (Solanum lycopersicum) under both normal and salt stress conditions. The most effective strain was identified through sequencing of the 16S rRNA, DNA topoisomerase II ATP-hydrolyzing DNA gyrase subunit B (gyrB) and DNA-directed RNA polymerase subunit beta (rpoB) loci. The results revealed that seven bacterial strains exhibited PGPR traits and antifungal activity. Among them, one strain significantly promoted the growth of A. spinosa and was identified as Providencia rettgeri. This strain enhanced tomato plant growth by increased plant height, stem diameter, and the number of internodes and leaflets under normal conditions, and it mitigated the detrimental effects of 150 mM NaCl. Additionally, it also suppressed the growth of Alternaria alternata in vitro and reduced disease severity by 55
The increasing frequency of extreme climatic events poses a major threat to global agriculture and food security. High-temperature stress affects plant growth, development, and productivity, making heat tolerance an important goal in crop improvement. Autophagy is a conserved process that degrades and recycles cellular material. By removing damaged proteins and organelles, it contributes to cellular protection during heat stress. Its contribution depends on the tissue, developmental stage, severity and duration of heat exposure, and recovery conditions. This review brings together evidence on ATG gene regulation, selective autophagy, protein quality control, and interactions with the ubiquitin-proteasome system. It compares experimental systems, heat treatments, and physiological outcomes to explain how autophagy contributes to thermotolerance. Particular attention is given to distinguishing increased ATG expression and autophagosome abundance from autophagic flux, which involves cargo delivery to and degradation within the vacuole. The review also examines how cargo selection and the timing of degradation influence the balance between immediate protection and tolerance to subsequent heat episodes. While clearance of damaged material supports cell survival, removal of heat-protective proteins during recovery can weaken the response to a later heat episode. This context dependence highlights the importance of regulating when, where, and which cellular components are degraded. Genome editing, molecular breeding, chemical treatments, and microbial priming offer possible ways to apply these findings in crop improvement. Their value will depend on establishing a clear link between altered autophagy and improved plant performance under relevant heat conditions. Direct evidence for plant microautophagy under heat stress remains lacking, while evidence from major cereal crops and field studies is still limited. These gaps define priorities for testing autophagy-based strategies for crop heat tolerance.
The sucking pest complex, including the leafhopper, Amrasca biguttula biguttula, whitefly, Bemisia tabaci, thrips Thrips tabaci, and aphids Aphis gossypii, are significant sap feeders on cotton, leading to substantial economic losses. Traditionally, these pests have been monitored using yellow sticky traps. However, variations in trap placement can affect the capture of sucking pests and their natural enemies. This study thoroughly assessed the impact of trap height (at canopy level (0), and 15, 30, 45, and 60 cm above the crop canopy) and trap position (interior versus periphery) on monitoring sucking pests and natural enemies in cotton fields. Our findings revealed that traps positioned at lower levels (0–15 cm above the canopy) captured significantly more A. biguttula (141.03 ± 1.12, 111.92 ± 3.85), B. tabaci (144.04 ± 6.81, 129.16 ± 5.89), T. tabaci (30.14 ± 1.51, 21.27), and A. gossypii (107.62 ± 4.75, 83.37 ± 4.02/trap/week, respectively) compared to those placed at 45 cm and higher. Additionally, natural enemies like coccinellids, tachinids, and chrysopids were less attracted to traps at canopy level than those positioned 45 cm and above. Furthermore, traps located in the interior of the canopy captured significantly more sucking pests than those at the periphery, while there were no notable differences in the attraction of natural enemies. These insights are crucial for enhancing the capture of A. biguttula, B. tabaci, T. tabaci, and A. gossypii while minimizing the impact on natural enemies in cotton fields.
The excessive reliance on synthetic fertilizers and pesticides has undeniably enhanced crop productivity; however, it has also led to long-term environmental degradation, highlighting the urgent need for sustainable alternatives. Bioinoculants, particularly indole acetic-producing bacteria, represent a promising eco-friendly approach to improving nutrient acquisition, plant health, and resistance to pathogens. In the present study, 15 bacterial species were isolated from agricultural and non-agricultural soils, among which four exhibited plant growth-promoting bacteria (PGPB) activity. Of these, Burkholderia dolosa (RBS11) and Pseudomonas aeruginosa (RBS15), identified through 16S rRNA gene sequencing, demonstrated the highest PGP potential. Both strains produced IAA as confirmed by GC-MS, analyses. In addition, they exhibited multiple plant growth-promoting (PGP) traits, including Siderophore synthesize and HCN production, as well as efficient phosphate solubilization. Treatment of S. lycopersicum seeds with the filtrate of IAA producing isolates significantly enhanced growth rate, biomass accumulation, chlorophyll content, and levels of secondary metabolites (phenolic and flavonoids), while also displaying antagonistic activity against Fusarium oxysporum. These findings position Burkholderia dolosa and Pseudomonas aeruginosa as multifunctional bio inoculants with dual roles in plant growth promotion and biocontrol, emphasizing their potential as key components in sustainable crop production systems.
Climate change is expected to intensify drought frequency and variability, threatening agricultural productivity and food security, particularly in vulnerable regions such as the Andean highlands. Quinoa (Chenopodium quinoa Willd.), a climate-resilient crop with high nutritional value, represents a promising alternative for sustainable food production under drought conditions. This study evaluated drought tolerance and plant growth-promoting rhizobacteria-mediated responses in nine Bolivian quinoa genotypes under growth chamber and greenhouse conditions. Plants were grown under well-watered (50
