Meixue Zhou

Zinc (Zn) deficiency is a common limiting factor in agricultural soils, which leads to significant reduction in both the yield and nutritional quality of agricultural produce. Exploring the quantitative trait loci (QTL) for shoot and grain Zn accumulation would help to develop new barley cultivars with greater Zn accumulation efficiency. In this study, two glasshouse experiments were conducted by growing plants under adequate and low Zn supply. From the preliminary screening of ten barley cultivars, Sahara (0.05 mg/pot) and Yerong (0.06 mg/pot) showed the lowest change in shoot Zn accumulation, while Franklin (0.16 mg/pot) had the highest change due to changes in Zn supply for plant growth. Therefore, the double haploid (DH) population derived from Yerong × Franklin was selected to identify QTL for shoot mineral accumulation and biomass production. A major QTL hotspot was detected on chromosome 2H between 31.91 and 73.12 cM encoding genes for regulating shoot mineral accumulations of Zn, Fe, Ca, K and P, and the biomass. Further investigation demonstrated 16 potential candidate genes for mineral accumulation, in addition to a single candidate gene for shoot biomass in the identified QTL region. This study provides a useful resource for enhancing nutritional quality and yield potential in future barley breeding programs.

Phosphorus (P), an essential macronutrient, plays a pivotal role in the growth and development of plants. However, the limited availability of phosphorus in soil presents significant challenges for crop productivity, especially when plants are subjected to abiotic stresses such as drought, salinity and extreme temperatures. Unraveling the intricate mechanisms through which phosphorus participates in the physiological responses of plants to abiotic stresses is essential to ensure the sustainability of agricultural production systems. This review aims to analyze the influence of phosphorus supply on various aspects of plant growth and plant development under hostile environmental conditions, with a special emphasis on stomatal development and operation. Furthermore, we discuss recently discovered genes associated with P-dependent stress regulation and evaluate the feasibility of implementing P-based agricultural practices to mitigate the adverse effects of abiotic stress. Our objective is to provide molecular and physiological insights into the role of P in regulating plants’ tolerance to abiotic stresses, underscoring the significance of efficient P use strategies for agricultural sustainability. The potential benefits and limitations of P-based strategies and future research directions are also discussed.

Osmotic stress that is induced by salinity and drought affects plant growth and development, resulting in significant losses to global crop production. Consequently, there is a strong need to develop stress-tolerant crops with a higher water use efficiency through breeding programs. Water use efficiency could be improved by decreasing stomatal transpiration without causing a reduction in CO2 uptake under osmotic stress conditions. The genetic manipulation of stomatal density could be one of the most promising strategies for breeders to achieve this goal. On the other hand, a substantial amount of water loss occurs across the cuticle without any contribution to carbon gain when the stomata are closed and under osmotic stress. The minimization of cuticular (otherwise known as residual) transpiration also determines the fitness and survival capacity of the plant under the conditions of a water deficit. The deposition of cuticular wax on the leaf epidermis acts as a limiting barrier for residual transpiration. However, the causal relationship between the frequency of stomatal density and plant osmotic stress tolerance and the link between residual transpiration and cuticular wax is not always straightforward, with controversial reports available in the literature. In this review, we focus on these controversies and explore the potential physiological and molecular aspects of controlling stomatal and residual transpiration water loss for improving water use efficiency under osmotic stress conditions via a comparative analysis of the performance of domesticated crops and their wild relatives.