Botrytis cinerea mediated cell wall degradation accelerates spike stalk browning in Munage grape

Abstract

Munage grape (Vitis vinifera L. cv. Munage.) is a unique cultivar in southern Xinjiang, China. Spike stalk browning in this species has becomes more common in recent years, negatively impacting the shelf life, and causing severe economic losses during storage.This study investigated the changes in metabolisms of cell wall by Botrytis cinerea infection in association with spike stalk browning. Morphological and physiological observations showed that preharvest B. cinerea infection accelerates the spike stalk browning during storage in Munage grapes by promoting cell wall degradation. Accordingly, the cell structures in infected spike stalk showed severe collapse, while the cell structures in uninfected spike stalk remained relatively complete. Furthermore, the contents of CDTA-soluble pectin (CSP), Na 2 CO 3 -soluble pectin (NSP), cellulose, and hemicellulose were reduced, while the water-soluble pectin (WSP) content was increased during infection. In addition, the activities of polygalacturonase (PG), pectin methylesterase (PME), beta-galactosidase (β-Gal), and cellulase (Cx) were highly promoted by B. cinerea.Correspondingly, the expression levels of VvPG were markedly upregulated after inoculation and played a major role in cell wall degradation. Additionally, the spike stalk inoculated by B. cinerea showed higher activities of PPO and POD, and content of total phenolics. These results contribute to elucidating the relationship between cell wall degradation induced by B. cinerea during spike stalk browning and provide a basis for future research on improving the ability of the host cell wall to resist degrading enzymes. Practical applicationsBotrytis cinerea is the main fungal pathogen causing the gray mold of grapes. It usually enters the tissue early in crop development, has a long incubation period, and rapidly infects the tissue when the environment is favorable and the host physiology changes.Gray mold has been reported as one of the major postharvest diseases of grapes.However, there are relatively few reports on the pathways through which B. cinerea causes the browning of grape stalks. Controlling browning caused by B. cinerea may require clarification of the physiological and molecular mechanisms by which browning occurs. The elucidation of the role of B. cinerea in causing browning of grape stalks through the cell wall degradation pathway will help to provide scientific basis for further controlling browning, maintaining freshness of stalks, developing biological agents to prevent browning, improving grape quality, and extending storage period.

Short-Term Gaseous Treatments Improve Rachis Browning in Red and White Table Grapes Stored at Low Temperature: Molecular Mechanisms Underlying Its Beneficial Effect

“…Furthermore, postharvest fruit senescence has been generally correlated with the activity of several cell wall-degrading enzymes [ 51 ]. Recently, Li et al [ 52 ] indicated the relationship between cell wall degradation induced by Botrytis cinerea and rachis browning. Moreover, the application of nano-calcium coupled with different concentrations of oxalic acid improved rachis browning, minimizing cell wall-degrading enzyme activities [ 39 ].…”

Integrated Characterization of Cassava (Manihot esculenta) Pectin Methylesterase (MePME) Genes to Filter Candidate Gene Responses to Multiple Abiotic Stresses

“…Similarly, PME genes in rice, rye and tea were induced by aluminum stress [10,[32][33][34]. Furthermore, PME gene expression was dynamically regulated during fruit ripening and postharvest storage [23,[35][36][37].…”

Inhibition of the Growth of Botrytis cinerea by Penicillium chrysogenum VKM F-4876D Combined with Fludioxonil-, Difenoconazole-, or Tebuconazole-Based Fungicides

“…Such preparations are the most suitable for inclusion in integrated plant protection because they are quite effective, selective, and safe [9,23]. Among microorganisms used for this purpose, those from the genera Penicillium and Bacillus are especially interesting since they synthesize various biologically active compounds [24,25] and are characterized by a wide range of antifungal activity [26,27]. Moreover, preparations based on these microorganisms are capable of growth-stimulating action (to some extent) and inducing plant defense mechanisms.…”