The combined use of the antagonistic yeast Hanseniaspora uvarum with β-aminobutyric acid for the management of postharvest diseases of kiwifruit

Significant losses in harvested kiwifruit can be directly attributed to decay fungi. In the present study, the use of an antagonistic yeast, Hanseniaspora uvarum, combined with beta-aminobutyric acid (BABA), a non-proteinogenic amino acid, was evaluated as a treatment for controlling postharvest infections of kiwifruit, artificially-inoculated with either Botrytis cinerea or Alternaria alternata. Natural infection of treated kiwifruits was also assessed. H. uvarum or BABA as stand-alone treatment, significantly reduced gray mold (B. cinerea) and black rot (A. alternata) on kiwifruit, relative to untreated control fruit, and also reduced the level of natural infection. The combination of H. uvarum and BABA, however, provided a superior level of postharvest disease control compared to either treatment alone. The growth of H. uvarum growth in kiwifruit wounds was not affected by BABA. Treatment of kiwifruit with either H. uvarum or BABA individually or in combination induced the gene expression and enzyme activity of chitinase and beta-1,3-glucanase in kiwifruit. The ability of BABA to enhance the biocontrol efficacy of H. uvarum may be partially attributed to the elicitation of defense response in kiwifruit. The combined use of H. uvarum and BABA represents a promising alternative approach to the use of synthetic fungicides for the control of postharvest diseases in kiwifruit.