Climate change and the resulting abiotic stresses that emerge due to anthropogenic activities are the main causes of agricultural losses worldwide. Abiotic stresses such as water scarcity, extreme temperatures, high irradiance, saline soils, nutrient deprivation and heavy metal contamination compromise the development and productivity of crops on a global scale. In this scenario, understanding the response of C4 plants to different abiotic stresses is of utmost importance, as they constitute major pillars of the global economy. To further our understanding of the response of C4 monocots, Setaria viridis and Setaria italica have gradually emerged as powerful model species for elucidating the physiological, biochemical, and molecular mechanisms of plant adaptation to abiotic stresses. This review integrates recent findings on the morphophysiological, transcriptomic, and metabolic responses of S. viridis and S. italica to drought, elevated heat and light, saline soils, nutrient deficiencies and heavy metal contamination. Comparative analyses highlight conserved and divergent stress-response pathways between the domesticated S. italica and its wild progenitor S. viridis. Together, these findings reinforce Setaria as a versatile C4 model for unraveling mechanisms of abiotic stress tolerance and highlight its potential as a genetic resource for developing climate-resilient cereal and bioenergy crops.

Among the most cultivated crops worldwide, potato ( Solanum tuberosum) faces significant threats from water scarcity, owing to its shallow root system and high irrigation requirement. Water deficit disturbs homeostasis and critical physiological mechanisms, including photosynthesis, carbohydrate translocation, and starch metabolism in tuberous plants. It reduces CO₂ assimilation, modulates the expression of key enzymes involved in starch synthesis, such as ADP-glucose pyrophosphorylase and starch synthases, and alters the amylose–amylopectin ratio, consequently affecting their rheological properties. Additionally, drought triggers antioxidant and metabolic responses in plants, including the accumulation of secondary metabolites and the regulation of stress tolerance-related genes. Transcriptomic analyses have revealed water-deficit responsive genes, such as StMAPK11 , StCDPK13 , and StERF94 , which contribute to stress adaptation. This review also explores mitigation strategies and genetic improvement approaches, including the application of biostimulants (chitosan, uniconazole), ZnO and SiO₂ nanoparticles, and the selection of more drought-tolerant genotypes. Recent advances in biotechnology, including gene editing and omics technologies, have contributed to the development of stress-resilient potato varieties.

Climate change and the resulting abiotic stresses that emerge due to anthropogenic activities are the main causes of agricultural losses worldwide. Abiotic stresses such as water scarcity, extreme temperatures, high irradiance, saline soils, nutrient deprivation and heavy metal contamination compromise the development and productivity of crops on a global scale. In this scenario, understanding the response of C₄ plants to different abiotic stresses is of utmost importance, as they constitute major pillars of the global economy. To further our understanding of the response of C₄ monocots, Setaria viridis and Setaria italica have gradually emerged as powerful model species for elucidating the physiological, biochemical, and molecular mechanisms of plant adaptation to abiotic stresses. This review integrates recent findings on the morphophysiological, transcriptomic, and metabolic responses of S. viridis and S. italica to drought, elevated heat and light, saline soils, nutrient deficiencies and heavy metal contamination. Comparative analyses highlight conserved and divergent stress-response pathways between the domesticated S. italica and its wild progenitor S. viridis. Together, these findings reinforce Setaria as a versatile C₄ model for unraveling mechanisms of abiotic stress tolerance and highlight its potential as a genetic resource for developing climate-resilient cereal and bioenergy crops.

Auxin is one of the major driving forces of plant development and requires careful regulation of transporter proteins to establish polar auxin transport. The PIN-FORMED ( PIN ) family plays a pivotal role in plant development by establishing auxin gradients that govern vascular patterning and organogenesis. However, the PIN family remains severely underexplored in Setaria viridis , a well-established model for C ₄ monocots. In this study, we identified and characterized 13 PIN genes in the S. viridis genome. Phylogenetic and collinearity analyses revealed duplication events in the SvPIN1, SvPIN5 and SvPIN10 subfamilies. Structural analysis uncovered unique features, including potential pseudogenization of SvPIN5a . Expression profiling across five developmental stages unveiled the potential developmental roles of SvPINs , with SvPIN1 and SvPIN10 paralogues predominantly expressed in shoots and panicles, SvPIN2 and SvPIN9 in roots, while SvPIN5b showed leaf-enriched expression, suggesting potential involvement in Kranz anatomy development. Hormonal treatments in callus cultures revealed auxin-mediated upregulation of SvPIN1b, SvPIN2, SvPIN5d, SvPIN8 and SvPIN10a . Our findings provide significant insights into the role of PIN genes in S. viridis and other C ₄ monocots, establishing a foundation for future functional studies and offering potential targets for crop improvement through auxin transport manipulation. Key Message: This study characterizes the PIN-FORMED auxin transporter family in the C ₄ model Setaria viridis , revealing gene duplication, tissue-specific expression, and hormonal regulation that may influence C ₄ traits.