Plants produce an array of different volatile organic compounds (VOCs) that have diverse eco-physiological functions and agricultural applications. Hence, the potential of VOCs as a natural and eco-friendly solution to increase crop productivity has garnered substantial attention. In particular, VOC-based pest management measures, such as Push–Pull, have been widely investigated in different cropping systems. However, our understanding of how the release and use of these VOCs impact agro-ecosystems beyond the targeted effects is still very limited. Therefore, studying the functions of plant VOCs from the perspective of pleiotropy may offer insights into optimizing and improving the effectiveness of VOC-based agronomic practices. Here, we discuss the current literature on the pleiotropic functions of plant VOCs, illustrate the underlying mechanism for their production and propose a systematic perspective for the usage of plant VOCs to enhance the sustainable management of crop health.

Salinity stress triggers changes in plant morphology, physiology and molecular responses which can subsequently influence plant-insect interactions; however, these consequences remain poorly understood. We analyzed plant biomass, insect population growth rates, feeding behaviors and plant gene expression to characterize the mechanisms of the underlying interactions between the rice plant and brown planthopper (BPH) under salinity stress. Plant bioassays showed that plant growth and vigor losses were higher in control and low salinity conditions compared to high salinity stressed TN1 (salt-planthopper susceptible cultivar) in response to BPH feeding. In contrast, the losses were higher in the high salinity treated TPX (salt-planthopper resistant cultivar). BPH population growth was reduced on TN1, but increased on TPX under high salinity condition compared to the control. This cultivar-specific effect was reflected in BPH feeding behaviors on the corresponding plants. Quantification of abscisic acid (ABA) and salicylic acid (SA) signaling transcripts indicated that salinity-induced down-regulation of ABA signaling increased SA-dependent defense in TN1. While, up-regulation of ABA related genes in salinity stressed TPX resulted in the decrease in SA-signaling genes. Thus, ABA and SA antagonism might be a key element in the interaction between BPH and salinity stress. Taken together, we concluded that plant-planthopper interactions are markedly shaped by salinity and might be cultivar specific.