Environmental Control in Tea Fields to Reduce Infection by Pseudomonas syringae pv. theae

Abstract

Bacterial shoot blight (BSB) disease, caused by Pseudomonas syringae pv. theae, is a major bacterial disease of tea plants in Japan. BSB mainly occurs in the low-temperature season, and lesion formation by P. syringae pv. theae is enhanced by both low temperature and the presence of ice nucleation-active Xanthomonas campestris (INAX), which catalyzes ice formation at -2 to -4 degrees C and is frequently co-isolated with P. syringae pv. theae from tea plants. Low temperature is thus the most important environmental factor influencing the incidence of BSB; however, the effects of low temperature on infection of the host by P. syringae pv. theae and of environmental controls in fields on the occurrence of the disease are poorly understood. In this study, we show that ice formation on tea leaves by INAX enhanced P. syringae pv. theae invasion into leaf tissue. The natural incidence of BSB in the field was closely related to early autumn frost. Frost protection in late autumn, which prevented ice formation on tea plants, significantly decreased the incidence of BSB, and frost protection combined with bactericide application held the incidence under the economic threshold level. Our data indicate that environmental control in the field based on microbial interactions in the host offers a new strategy for plant disease control.

Transcriptomic, Biochemical, and Morphological Study Reveals the Mechanism of Inhibition of Pseudopestalotiopsis camelliae-sinensis by Phenazine-1-Carboxylic Acid

“…camelliae-sinensis is known to be the dominant pathogen for this disease in China (Maharachchikumbura et al, 2014;Chen et al, 2017Chen et al, , 2018aLiu et al, 2017). Currently, chemical fungicides are the main strategy to prevent and control the disease, but the problem of increased risks of pesticide residues in tea leaves has attracted negative attention (Horikawa, 1986;Oniki et al, 1986;Shin et al, 2000;Tomihama et al, 2009;Yamada et al, 2016). The biocontrol agents, Trichoderma harzianum, Gliocladium virens, and Pseudomonas fluorescens, have been used to prevent and effectively manage TGB (Sanjay et al, 2008).…”

Frost promotes the pathogenicity of Pseudomonas syringae pv. actinidiae in Actinidia chinensis and A. deliciosa plants

“…Frost events alone or in combination with strains of P. syringae pathovars (i.e. primarily the pathovar syringae ) are considered as a major predisposing factor(s) for the initial colonization of resident bacterial pathogens and/or the subsequent penetration of phytopathogens (De Kam, ; Vigoroux, ; Sobiczewski & Jones, ; Tomihama et al ., ). Spring seasons with frequent rains and/or high humidity have also contributed to rapid Psa multiplication in Japan (Serizawa & Ichikawa, ).…”

Are we killing the rain? Meditations on the water cycle and, more particularly, on bioprecipitation

“…5. P. syringae received sustained research attention, therefore, as an aggressive and successful pathogen responsible for basal kernel blight in respect to barley (Braun-Kiewnick et al 2000); as a principal causal agent of halo blight in many bean cultivars (Bozkurt and Soylu 2011); as a prolific cause of bacterial shoot blight in tea plants, widely infecting them in tea-growing countries such as Japan (Tomihama et al 2009); and as an antagonist of tomato plants, on which it causes a blight called bacterial speck across the world (see e.g. de-Bashan 2002a, 2002b with the author.…”