Austropuccinia psidii infection changes stomatal dynamics and leaf gas exchange of guava leaves: A physio-histopathological assessment

Author(s)

Goncalves, Manoel Penachio ; Amorim, Lilian ; Ribeiro, Rafael Vasconcelos ; Misaki Soares, Marli Kasue ; Appezzato-da-Gloria, Beatriz

• Document type: Journal article
• Source: PHYSIOLOGICAL AND MOLECULAR PLANT PATHOLOGY; v. 128, p. 8-pg., 2023-10-09.

Abstract

This study aimed to characterise the life cycle of Austropuccinia psidii, the causal agent of myrtle rust, in guava cv. Paluma and to determine how this pathogen affects gas exchange in diseased leaves. The pathogen formed appressoria on ordinary epidermal cells and intercellular hyphae and intracellular branched lobe-shaped haustoria in parenchyma cells. In the stem, hyphae grew in the cortical region and crossed between tracheary cells, reaching the medullary region. In the leaf, hyphae colonised the intercellular spaces of the main vein and mesophyll and the substomatal chamber. Colonisation of the substomatal chamber by A. psidii changed the stomatal dynamics and leaf gas exchange. The stomatal response to light was slower and had a smaller amplitude in diseased guava leaves. Consequently, impaired stomatal movement induced by A. psidii is an additional factor changing the performance of plants under abiotic stress. (AU)

• FAPESP's process: 19/13191-5 - Epidemiological components, damage characterization and control of tropical and temperate rusts at a global climate change scenario
• Grantee: Marcel Bellato Spósito
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 22/02460-8 - Occurrence of guava rust in a scenario of temperature increase and water deficit imposed by global climate change
• Grantee: Manoel Penachio Gonçalves
• Support Opportunities: Scholarships in Brazil - Doctorate