Abiotic Stress Tolerance in Citrus Plants

Citrus species underpin a multibillion‐dollar horticultural sector yet remain vulnerable to a spectrum of abiotic stresses, notably drought, soil salinity, temperature extremes and waterlogging. Tolerance arises from an interplay of physiological adjustments—such as stomatal regulation, osmotic adjustment and ion exclusion—and biochemical defences including enhanced antioxidant enzyme activities and compatible solute accumulation. Hormonal signals, particularly abscisic acid and salicylic acid, orchestrate stress‐responsive gene expression, while rootstock–scion interactions modulate water and nutrient uptake. Advances in polyploid breeding, grafting techniques and omics‐driven gene discovery have illuminated key tolerance mechanisms. In practice, selecting appropriate rootstocks, deploying optimised irrigation regimes and integrating genetic improvements offer sustainable routes to safeguard yield and quality under adverse environmental conditions.

Research from Nature Portfolio

Foundational work has dissected drought survival strategies in contrasting citrus rootstocks subjected to severe water deficit and rehydration cycles. One study employed reciprocal grafting between a dehydration‐avoidant genotype and a dehydration‐tolerant genotype to reveal that tolerance is conferred by elevated abscisic acid and salicylic acid levels, accumulation of protective carbohydrates (such as trehalose and raffinose) and robust antioxidant enzyme activities. These traits not only underlie intrinsic rootstock resilience but also can be transmitted to grafted scions, facilitating rapid recovery after prolonged drought.

Abiotic Stress Tolerance in Citrus Plants publication trend

The graph below shows the total number of articles in abiotic stress tolerance in citrus plants across all publications each year (not limited to Nature Index journals).

Technical terms

Osmotic adjustment: The process by which plant cells accumulate solutes to maintain turgor and water uptake under conditions of water deficit or high salinity.

Reactive oxygen species (ROS): Highly reactive molecules derived from oxygen that can cause cellular damage but also serve as signalling messengers in stress responses.

Polyploidy: The state of possessing more than two complete sets of chromosomes, often associated with enhanced vigour and stress resilience in plants.

Rootstock–scion interaction: The physiological and molecular dialogue between the rootstock and the grafted shoot, which influences water, nutrient and hormonal dynamics under stress.

Abscisic acid (ABA): A key phytohormone that regulates stomatal closure, gene expression and osmotic balance during drought and salinity stress.

References

1. Insight into Physiological and Biochemical Determinants of Salt Stress Tolerance in Tetraploid Citrus. Antioxidants (2023).
2. Novel and widely spread citrus rootstocks behavior in response to salt stress. Environmental and Experimental Botany (2024).
3. Survival strategies of citrus rootstocks subjected to drought. Scientific Reports (2016).
4. Comparative transcriptome analysis reveals synergistic and disparate defense pathways in the leaves and roots of trifoliate orange (Poncirus trifoliata) autotetraploids with enhanced salt tolerance. Horticulture Research (2020).
5. Drought and Salinity in Citriculture: Optimal Practices to Alleviate Salinity and Water Stress. Agronomy (2021).