Interactive Responses of Potato (Solanum tuberosum L.) Plants to Heat Stress and Infection With Potato Virus Y

Abstract

Potato (Solanum tuberosum) plants are exposed to diverse environmental stresses, which may modulate plant–pathogen interactions, and potentially cause further decreases in crop productivity. To provide new insights into interactive molecular responses to heat stress combined with virus infection in potato, we analyzed expression of genes encoding pathogenesis-related (PR) proteins [markers of salicylic acid (SA)-mediated plant defense] and heat shock proteins (HSPs), in two potato cultivars that differ in tolerance to elevated temperatures and in susceptibility to potato virus Y (PVY). In plants of cv. Chicago (thermosensitive and PVY-susceptible), increased temperature reduced PR gene expression and this correlated with enhancement of PVY infection (virus accumulation and symptom production). In contrast, with cv. Gala (thermotolerant and PVY resistant), which displayed a greater increase in PR gene expression in response to PVY infection, temperature affected neither PR transcript levels nor virus accumulation. HSP genes were induced by elevated temperature in both cultivars but to higher levels in the thermotolerant (Gala) cultivar. PVY infection did not alter expression of HSP genes in the Gala cultivar (possibly because of the low level of virus accumulation) but did induce expression of HSP70 and HSP90 in the susceptible cultivar (Chicago). These findings suggest that responses to heat stress and PVY infection in potato have some common underlying mechanisms, which may be integrated in a specific consolidated network that controls plant sensitivity to multiple stresses in a cultivar-specific manner. We also found that the SA pre-treatment subverted the sensitive combined (heat and PVY) stress phenotype in Chicago, implicating SA as a key component of such a regulatory network.

Heat Shock Proteins: Dynamic Biomolecules to Counter Plant Biotic and Abiotic Stresses

“…A recent study on Potato Virus Y (PVY) in potato thermo-tolerant and sensitive genotypes under heat stress, HSPs was induced in both genotypes. Regarding thermo-tolerant genotypes, the expression of PR genes was also high, resulting in less viral infection [117]. Resistance against viral infection in Cytosinpeptidemycin application for the control of Rice Black Streaked Dwarf Virus (RBSDV), along with other defense-related genes, antioxidant enzymes and HSP also were up-regulated to control the virus infection [115].…”

Interaction of a plant virus protein with the signature Cajal body protein coilin facilitates salicylic acid‐mediated plant defence responses

“…There is a high degree of cross-kingdom functional conservation of subnuclear bodies. Both the nucleolus and CBs have been implicated in responses to a wide range of biotic and abiotic stresses (Boulon et al, 2010;Bassett, 2012;Love et al, 2017;Makarova et al, 2018). It will be of substantial interest to discover the extent to which coilin operates as a mediator for sensing and triggering of defence against these stresses in plants and other eukaryotic systems.…”

Role of the methionine cycle in the temperature‐sensitive responses of potato plants to potato virus Y

“…With regard to PVY, we have recently shown that susceptibility of potato cv. Chicago plants to systemic PVY infection (virus accumulation and symptom production in systemically infected leaves) is significantly enhanced by elevated temperature compared with normal conditions (Makarova et al, 2018). Interestingly, such an enhanced susceptibility was correlated with reduced expression of genes encoding pathogenesis-related (PR) proteins, which are hallmarks of salicylic acid (SA)-mediated plant defence responses.…”