Enhancing crop resilience to combined abiotic and biotic stress through the dissection of physiological and molecular crosstalk

Abstract

Plants growing in their natural habitats are often challenged simultaneously by multiple stress factors, both abiotic and biotic. Research has so far been limited to responses to individual stresses, and understanding of adaptation to combinatorial stress is limited, but indicative of non-additive interactions. Omics data analysis and functional characterization of individual genes has revealed a convergence of signaling pathways for abiotic and biotic stress adaptation. Taking into account that most data originate from imposition of individual stress factors, this review summarizes these findings in a physiological context, following the pathogenesis timeline and highlighting potential differential interactions occurring between abiotic and biotic stress signaling across the different cellular compartments and at the whole plant level. Potential effects of abiotic stress on resistance components such as extracellular receptor proteins, R-genes and systemic acquired resistance will be elaborated, as well as crosstalk at the levels of hormone, reactive oxygen species, and redox signaling. Breeding targets and strategies are proposed focusing on either manipulation and deployment of individual common regulators such as transcription factors or pyramiding of non- (negatively) interacting components such as R-genes with abiotic stress resistance genes. We propose that dissection of broad spectrum stress tolerance conferred by priming chemicals may provide an insight on stress cross regulation and additional candidate genes for improving crop performance under combined stress. Validation of the proposed strategies in lab and field experiments is a first step toward the goal of achieving tolerance to combinatorial stress in crops.

Salicylic acid application modulates physiological and hormonal changes in Eucalyptus globulus under water deficit

“…Preliminary studies 21 performed by our research group already indicated the detrimental 22 effects of drought conditions in E. globulus plants (decreased water 23 potential, reduced gas exchange rates and stomatal conductance, 24 enhanced lipid peroxidation, among others) and correlated this 25 stress responses with changes in hormonal contents, namely 26 abscisic acid (ABA) and jasmonic acid (JA) (Correia et al, 2014a,b). 27 Understanding how planted forest trees tolerate low water 28 availability, studying new insights to anticipate its impacts and al pathways (Kissoudis et al, 2014) lead to changes in the biological 48 responses for the maintenance of plant stress tolerance (Wang and (Pastor et al, 1999). 61 The exogenous application of SA has been considered a short-62 term solution to improve the adverse effects of water deficit on 63 plants (Singh and Usha, 2003), however the precise mode of SA 64 action remains unclear (Hayat et al, 2010), in particular for trees.…”

Genome Editing in Plants: An Overview of Tools and Applications

“…Genome editing technologies have wide practical applications for solving one of the most important tasks of modern biotechnology-the creation of new varieties of crops, which are high-yielding and resistant to abiotic and biotic stresses and also have high nutritional value (Table 2) [31,63,[75][76][77][78][79][80]. To this end, genome editing system has been used in plant breeding (1) to insert point mutations similar to natural SNPs [26,27], (2) to make small modifications to gene function [13], (3) for integration of foreign genes, (4) for gene pyramiding and knockout, and (5) for the repression or activation of gene expression, as well as (6) epigenetic editing [6].…”

Crosstalk of brassinosteroids with other phytohormones under various abiotic stresses

“…Interactive effects of BRs and auxin involved physiological process such as hypocotyl elongation or root development. However, still, BR interaction with auxin in regulating stress responses has remained indefinable [67]. In Arabidopsis, the BR level required for development is interceded by BRAVIS RADIX (BRX) which is provoked by auxin showing that BRX demonstrations at the nexus of an input circle in Arabidopsis [68].…”