Journal of Plant Growth Regulation

Arif, Muhammad; Men, Shuzhen; Nawaz, Ayesha Fazal; Li, Xin; Xu, Ling; Yang, Xuemin; Fahad, Shah; Ahmad, Parvaiz; Xu, Ruhong; Li, Luhua

doi: 10.1007/s00344-024-11524-3pmid: N/A

Plant stress responses control programmed cell death (PCD) pathways, potentially targeting crop improvement against environmental challenges, while maintaining intracellular protein homeostasis is crucial for survival. Because intracellular proteins are regularly damaged and lose functioning under stressful conditions, molecular chaperones serve as vital for life support because they maintain protein structure and function. Bcl-2-associated athanogenes (BAGs) are a multifunctional group chaperones distinguished by a common conserved BAG domain sequence. This review provides an extensive analysis of recent advancements in the study of plant BAGs, elucidating their versatile roles in plant biology. Plant BAGs are involved in many cellular processes, including stress response, cellular homeostasis, and plant development. Our perspective on plant BAGs has just been updated. Recently, we reported that AtBAG2 and AtBAG6 enable to tolerate Arabidopsis thaliana to multiple abiotic stresses. This review synthesizes the most recent research on the functional aspects of BAGs in different plant species, including Arabidopsis, tomato, rice, maize, wheat, chickpea, tobacco, banana, soybean, grapes, and mosses, highlighting their diverse interactions with signaling pathways and stress responses. This study explores the physiological functions of plant BAG proteins, highlighting challenges in unraveling BAG-mediated processes and the importance of advanced research approaches for sustainable agriculture, stress tolerance, and crop improvement. This study emphasizes the potential of plant BAG genes in addressing global food security and climate change, promoting additional research and discovery to open up new possibilities.

Zhang, Rongrong; Luo, Shilei; Li, Long; Mu, Tingting; Wang, Peng; Zhang, Guobin

doi: 10.1007/s00344-025-11827-zpmid: N/A

As a key signaling molecule in plants in response to drought stress, ABA activates a complex downstream signaling network by specifically binding to members of the PYL protein family. In turn, it precisely regulates physiological processes such as stomatal closure, leaf senescence, water use efficiency, and osmotic adjustment, significantly improving plant drought tolerance. This paper describes the central role of PYL receptors in enhancing drought tolerance in plants by increasing their sensitivity to ABA (abscisic acid) and the mechanisms involved. In addition, the synergistic action of PYL and ABA also mediated the induction of growth inhibition and dormancy in plants, allowing them to adopt adaptive growth strategies to slow metabolic rates and store energy under drought conditions. Nevertheless, the synergistic effect of PYL and ABA also inhibits the drought resistance of plants. This review aims to deepen the understanding of the molecular mechanism by which PYL and ABA synergistically regulate drought resistance in plants and to provide a theoretical basis and practical way for the use of genetic engineering technology to improve drought resistance in crops.

Saeed, Muhammad

doi: 10.1007/s00344-025-11829-xpmid: N/A

Climate change poses a substantial threat to crop productivity, agricultural sustainability, food security, and human health. Such issues have become even more lethal in the South Asia region, where the predicted average increase in temperature is 1.5–3.0 °C. Heat stress causes multifaceted impacts on physiological, cellular, and molecular levels from the vegetative phase to grain filling in cereal crops. To cope with stress, crops synthesize various mechanisms like osmolyte synthesis, signal transduction, antioxidants, ascorbate–glutathione cycle, and the expression of heat-responsive genes. Several quantitative trait loci (QTLs) have been linked with heat stress for traits like pollen fertility, grain filling duration, grain weight, and grain yield. Integrating multi-omics methods, mainly transcriptomics, proteomics, metabolomics, and high-throughput phenomics, can further elucidate tolerance mechanisms in crops under heat stress. Furthermore, discovering microRNAs (miRNAs) paves the way for generating heat stress tolerance through advanced genome editing tools. Overexpression of miR157, miR158, miR159, miR164, and miR398 causes sensitivity towards heat stress by inducing oxidative stress and interfering with defense mechanisms. On the other hand, overexpression of miR157, miR160, and miR393 generates tolerance by regulating heat shock proteins. CRISPR-Cas9 can use such miRNA-based targets either by knocking them out or inserting them into the genome to improve heat resilience in crops. This review delivers comprehensive knowledge on integrating multi-omics approaches to understand heat response in wheat, rice, and maize. This review also highlights key target genes and miRNAs available for genome CRISPR-Cas9 to enhance heat tolerance. Furthermore, the review emphasizes the screening and breeding of heat-tolerant genotypes for sustainable agriculture and food security.

Ullah, Izhar; Hamza, Muhammad; ul Ain, Noor; Mohamed, Heba I.; Muhammad, Murad; Sultan, Yaqoob; Khan, Muskan Alam; Basit, Abdul

doi: 10.1007/s00344-025-11834-0pmid: N/A

Abiotic stress, like low temperature, adversely affects growth, development, survival, and crop yields, contributing to global food insecurity. Cold stress adversely affects plants in various processes, including low seed germination rate, stunted growth of seedlings, wilting, chlorosis, and necrosis. Conversely, temperatures above the growth-optimal range can negatively impact plant functions and cellular machinery by disrupting cellular balance due to high dehydration in freezing conditions. Cold stress can significantly impact plant yields, often leading to a reduction of 20–30%. Studies have shown that cold stress can cause grain yield losses of up to 38.6%. The impact of cold stress can vary depending on the specific crop, the stage of development when the stress occurs, and the severity of the cold. Jasmonic acid (JA), a plant hormone derived from lipids, is crucial in enhancing cold stress tolerance in horticultural crops. This review summarizes the recent advancements regarding JA-mediated induction of cold stress tolerance in horticultural crops. The review discusses the multifaceted roles of JA in influencing complex signaling pathways, antioxidant defense mechanisms, and modulation of osmolyte production. Furthermore, the review explores the crosstalk of JA with other plant hormones in altered stress responses. Finally, the review highlights the potential of manipulating JA biosynthesis or signaling for developing stress-resilient horticultural cultivars. Overall, this review underscores the significance of JA as a potent elicitor for inducing abiotic stress tolerance in horticultural crops, paving the way for future research endeavors to exploit JA-based strategies for horticultural crop improvement in the face of a changing climate.

Thakur, Gitika; Singh, Pradeep; Sharma, Vishal; Sharma, Ankush; Singh, Jagveer; Kumar, Satish

doi: 10.1007/s00344-025-11838-wpmid: N/A

Citrus, a globally significant horticultural crop, faces increasing challenges from drought-stress driven by climate variability and anthropogenic activities. Drought disrupts key developmental processes in citrus such as flowering and bud break, ultimately reducing fruit yield and quality. This review explores the molecular mechanisms underlying citrus responses to drought, emphasizing the regulatory role of phytohormones. Key hormones, abscisic acid (ABA), jasmonic acid (JA), auxins, cytokinins (CK), gibberellins (GA), ethylene (ET), salicylic acid (SA), brassinosteroids (BR), and strigolactones (SLs) coordinate adaptive responses through complex cross-talk and transcriptional networks. Notably, drought stress induces the expression of Citrus FLOWERING LOCUS T (CiFT) and its alternative splicing isoform Citrus FLOWERING LOCUS D (CiFDβ), promoting drought-mediated flowering independently of conventional florigen pathways. CiFRI, a homolog of FRIGIDA, further enhances drought tolerance while delaying flowering, highlighting a dual regulatory role. ABA signaling, involving PYR/PYL receptors, PP2Cs, and SnRK2 kinases, is central to mediating stomatal closure and reactive oxygen species (ROS) detoxification. The interplay between JA and ABA promotes early drought responses, while BR signaling reinforces ABA and auxin pathways but suppresses JA accumulation to balance growth and defense. Concurrently, cytokinin downregulation reallocates resources toward root development, improving water uptake under stress conditions. Transcription factors such as NF-Y complexes, WRKY70, bZIPs, and MYBs integrate hormonal signaling with stress-responsive gene regulation, modulating flowering and antioxidant defenses. This review provides an integrated perspective on the molecular networks shaping drought stress adaptation in citrus and identifies key targets for the development of drought-resilient cultivars through genetic and biotechnological strategies.

Parveen, Zeba; Zaidi, Sameen; Bajguz, Andrzej; Arif, Yamshi; Hayat, Shamsul

doi: 10.1007/s00344-025-11841-1pmid: N/A

Flavonoids are a significant class of secondary metabolites widely present in plants, playing a crucial role in their growth and development while also finding extensive applications in food and medicine. These compounds consist of two phenyl A- and B-rings and a heterocyclic C-ring, containing oxygen, forming a 15-carbon skeleton represented by C6–C3–C6 (diphenylpropane). Based on their molecular structure, degree of unsaturation, and oxidation state of the carbon ring, flavonoids are classified into several categories, including flavones, flavanones, isoflavones, flavonols, chalcones, and anthocyanins. Plants synthesize flavonoids through the phenylpropanoid pathway and transport them via three main mechanisms: membrane transport proteins, vesicles, and glutathione S-transferase conjugates. Flavonoids mediate various biological activities in plants, protecting them from abiotic stresses (e.g., heavy metals, drought, salinity, UV radiation, heat, and cold) and biotic threats (e.g., bacteria, fungi, and plant-parasitic nematodes). This review explores the distribution, biosynthesis, isolation, characterization, and subclasses of flavonoids. Additionally, it discusses the multi-level regulation of flavonoid biosynthesis, including transcriptional and epigenetic mechanisms, as well as other regulatory factors such as light, low temperature, sugar availability, and nutrient deficiency. Finally, the interaction of flavonoids with plant growth regulators (PGRs) is examined.

Yadav, Manisha; Singh, Archana

doi: 10.1007/s00344-025-11848-8pmid: N/A

Plants, being sessile, have evolved intricate defense mechanisms to cope up with biotic stresses. These defense mechanisms are often regulated by complex signalling pathways and their crosstalk. Secondary messengers such as Ca2+, H2O2 and other Reactive Oxygen Species (ROS) are key mediators and act concomitantly in receiving extracellular signals and generating specific defense responses through long/short distance signal transmission. The spatiotemporal regulation of Ca2+ concentrations, coordinated by various cellular components, is crucial for initiating specific defense responses within the cell. The decoding and relay of Ca²⁺ signals are mediated by Ca²⁺ sensors and responder proteins, which trigger downstream cellular responses. Additionally, ROS are generated in response to various biotic stresses, which serve as key players in the complex network of signalling events and the interplay between ROS and Ca2+-signalling pathways intensify each other for fine-tuning the signalling network in inciting plant defense response. Ca2+-sensor proteins act as potential molecular switches, which link these signalling pathways as well as molecular machinery responsible for synergistic interaction between ROS and Ca2+-signals. In this review, we briefly touch on the crosstalk of Ca2+ and ROS signalling pathways during defense responses to underscore the complexity of the cellular signalling network. Understanding these signalling pathways along with their crosstalk and the molecular mechanisms underlying plant immune response, is crucial for developing strategies to enhance crop resilience and productivity.

Yadav, Radheshyam; Ramakrishna, Wusirika

doi: 10.1007/s00344-025-11853-xpmid: N/A

This comprehensive review critically examines the role of the microbiome in mediating drought and salt tolerance, delving into the associated molecular mechanisms. Furthermore, it explores the impact of abiotic stress on the soil microbial community, considering its repercussions and the identification of responsive microbes. The potential application of Synthetic Microbial Communities (SMCs) to enhance agricultural crop yield is discussed. Tailored microbial consortia can enhance plant tolerance against drought and salt stress. A framework for developing synthetic biology solutions to combat these challenges in the dynamic climate crisis is proposed, including strategies to mitigate stress conditions in plants. Synthetic biology enables the design of customized microbial communities with specific functionalities to induce stress-responsive pathways in plants. This approach holds promise for developing sustainable solutions and enhancing crop productivity in the face of abiotic stress. The review highlights the crucial need to raise awareness and garner support from farmers and policymakers, urging them to embrace the recommendations and implement them in field conditions.

Sousa, Raysa M. J.; Henschel, Juliane M.; Batista, Diego S.; Silva, Tatiane D.; Felipe, Sérgio H. S.; Torres-Silva, Gabriela; Souza, Paulo V. L.; Cândido-Sobrinho, Silvio A.; Chagas, Kristhiano; Castro, Kamila M.; Fortini, Evandro A.; Correia, Ludmila N. F.; Brito, Danielle S.;

Mguis, Khaled; Abassi, Mejda; Enneb, Hanen; Albouchi, Ali; Chaffei-Houari, Chiraz

doi: 10.1007/s00344-025-11830-4pmid: N/A

Crithmum maritimum is an edible halophyte plant that is not only able to tolerate a high rate of salinity but also to survive and grow normally in hypersaline environments. The present study evaluates how nitrogen metabolism is involved in the salt stress response in halophytes. The plants previously cultured for 15 days in a basal medium were subjected to various concentrations of NaCl (0, 100, 200 and 300 mM) for a period of one month. Other plants were exposed to 300 mM of NaCl for three weeks, and then placed once again in basic culture medium without NaCl (R) for one week. The results showed that Crithmum maritimum could tolerate 100 mM of NaCl with efficient carbon and nitrogen assimilation. In addition, applying 100 mM NaCl induced asparagine synthetase protein, correlating to an increase in asparagine levels recorded in the shoots. However, salinity's inhibitory effect intensified when halophytes were treated with 300 mM NaCl. This caused progressive reduction of nitrogen-assimilating enzymes (nitrate reductase, nitrite reductase, and glutamate synthase). Interestingly, transferring plants previously treated with 300 mM NaCl to a basic control medium allowed plants to partially recover their growth and nitrogen metabolism status.