Xanthomonas oryzae pv. oryzae type III effector PthXo3JXOV suppresses innate immunity, induces susceptibility and binds to multiple targets in rice

Abstract

Transcription activator-like (TAL) effectors encoded by tal genes were recognized as a key virulence strategy used by Xanthomonas oryzae pv. oryzae (Xoo) to cause bacterial leaf blight of rice. TAL effector PthXo3 is a major virulence factor identified in a Philippine Xoo strain PXO61, and it can induce the expression of susceptibility gene OsSWEET14 by binding to the effector-binding element (EBE) in the promoter region. In this study, pthXo3 homologous genes were also identified and isolated from Xoo Chinese strain OS198 and Japanese strain JXOV, which were named as pthXo3OS198 and pthXo3JXOV, respectively. When pthXo3JXOV was delivered into PXO99A, the resulting strain PXO99A/pthXo3JXOV significantly increased virulence in 18 out of 23 rice varieties tested, with the most prominent increase in lesion length and bacteria propagation in rice IRBB13. PthXo3JXOV suppresses the plant's innate immunity by inhibiting hypersensitive response (HR) and callose deposition. The Agrobacterium tumefaciens-mediated transient expression assays showed that, besides OsSWEET14, PthXo3JXOV also interacts with other targets by binding to the EBEs in their promoter regions. Our results suggest that PthXo3JXOV may interact with multiple targets to execute its virulence functions.

Tal2b targets and activates the expression of OsF3H03g to hijack OsUGT74H4 and synergistically interfere with rice immunity

“…As a model system of plant–pathogen interactions, TAL and non‐TAL effectors in rice– Xanthomonas interactions have received widespread attention (Niño‐Liu et al ., 2006). Previously studies have identified numerous TAL effectors in Xoo that act as virulence factors, including Avrxa5 (Bai et al ., 2000), AvrXa7 (Yang et al ., 2000), PthXo1 (Yang et al ., 2006), PthXo6 and PthXo7 (Sugio et al ., 2007), Tal5 (Streubel et al ., 2013), PthXo2 (Zhou et al ., 2015), TalB (Tran et al ., 2018), TalC (Doucouré et al ., 2018), and PthXo3JXOV (R. Li et al ., 2018). Although there are more than 28 TAL effectors in several Xoc strains (Wilkins et al ., 2015), they have not received sufficient attention like TAL effectors in Xoo strains.…”

Design, synthesis and antibacterial activities against Xanthomonas oryzae pv. oryzae, Xanthomonas axonopodis pv. Citri and Ralstonia solanacearum of novel myricetin derivatives containing sulfonamide moiety

“…The major bacteria causing leaf blight in rice is Xanthomonas oryzae pv. o ., a bacteria that can cause damage at any stage of the life cycle, resulting in a serious decline in the crop yield . One of the main diseases affecting tobacco plants in tropical and subtropical regions (tobacco wilt) is caused by Ralstonia solanacearum .…”

The Type III Accessory Protein HrpE of Xanthomonas oryzae pv. oryzae Surpasses the Secretion Role, and Enhances Plant Resistance and Photosynthesis

“…Several TAL effectors from Xoo have been reported to be major virulence factors that may activate the expression of susceptibility genes ( S ) during infection. The key virulence factor of the Xoo strain PXO99 A in rice is PthXo1 [17].…”