Plant responses to concurrent abiotic and biotic stress: unravelling physiological and morphological mechanisms

With the increasing impact of climate change and global warming, not only abiotic stress factors have gained prominence, but their influence on plant–biotic interaction has also increased. Plants respond differently to abiotic factors compared to pests and pathogens, which thrive under intense climatic conditions, leading to higher disease susceptibility and potential epidemic outbreaks. Therefore, a comprehensive understanding of the effects of concurrent biotic and abiotic stress on plants is essential. Despite its significance, there have been limited studies on the physiological and morphological responses of plants to combined stress, and the underlying molecular mechanisms remain elusive. While model crops like rice and maize have been explored under the context to some extent there is a scarcity of research on other crops. Furthermore, the impact of environmental factors on physiological changes in plants remains largely unknown. This review aims to consolidate existing literature on this topic, with a focus on interaction between abiotic stresses (drought, heat, and salinity) and biotic stresses (pathogens and pests). Additionally, it highlights agriculturally important morpho-physiological traits that can be utilized to identify genotypes with combined stress tolerance. Moreover, the review will outline the potential role of recent techniques and genomic tools in unravelling combined stress tolerance in plants. The findings of this review will help physiologists and molecular biologists to design agronomically relevant strategies for developing broad-spectrum stress-tolerant crops.