Monitoring of Rice Transcriptional Responses to Contrasted Colonizing Patterns of Phytobeneficial Burkholderia s.l. Reveals a Temporal Shift in JA Systemic Response

Abstract

In the context of plant–pathogen and plant–mutualist interactions, the underlying molecular bases associated with host colonization have been extensively studied. However, it is not the case for non-mutualistic beneficial interactions or associative symbiosis with plants. Particularly, little is known about the transcriptional regulations associated with the immune tolerance of plants towards beneficial microbes. In this context, the study of the Burkholderia rice model is very promising to describe the molecular mechanisms involved in associative symbiosis. Indeed, several species of the Burkholderia sensu lato (s.l.) genus can colonize rice tissues and have beneficial effects; particularly, two species have been thoroughly studied: Burkholderia vietnamiensis and Paraburkholderia kururiensis. This study aims to compare the interaction of these species with rice and especially to identify common or specific plant responses. Therefore, we analyzed root colonization of the rice cultivar Nipponbare using DsRed-tagged bacterial strains and produced the transcriptomes of both roots and leaves 7 days after root inoculation. This led us to the identification of a co-expression jasmonic acid (JA)-related network exhibiting opposite regulation in response to the two strains in the leaves of inoculated plants. We then monitored by quantitative polymerase chain reaction (qPCR) the expression of JA-related genes during time course colonization by each strain. Our results reveal a temporal shift in this JA systemic response, which can be related to different colonization strategies of both strains.

Diverse Roles of MAX1 Homologues in Rice

“…In the promoter region of Os01g0701500 the second highest number of specific TF binding motifs were found, however some TF groups (TFmatrixID_0386, TFmatrixID_0388, TFmatrixID_0389, TFmatrixID_0390, TFmatrixID_0395; as well as TFmatrixID_0524, TFmatrixID_0547) were represented by the same representatives ( Table S5 ). Identified TFs, were involved in plant responses to various biotic stresses, including viruses [ 66 ], bacteria [ 92 ] and fungi [ 68 ] and different abiotic stresses ( Table S5 ). Among TFs related to abiotic stresses, those involved in iron [ 65 , 93 ] and nitrogen deficiency [ 63 , 64 , 94 ], response to cold [ 95 ], drought [ 54 , 55 , 96 , 97 ], salt [ 58 , 60 , 98 ], cadmium [ 62 ], chromium [ 99 ], submergence [ 100 ] were found.…”

“…Another gene from Os01g0700900 CGN: Os03g0368900 (MR = 85.229) encoding a peroxidase precursor is involved in ROS homeostasis in rice and is under the control of MADS3 (Os01g0201700) that regulates late anther development and pollen formation [ 153 ]. Finally, Os10g0390800 (MR = 94.106), encoding another peroxidase ( Table S10 ), plays the role in rice response to drought [ 56 ], phosphorus starvation [ 88 ] and bacterial infection [ 92 ] ( Table 3 ).…”

Genetic Diversity of Type 3 Secretion System in Burkholderia s.l. and Links With Plant Host Adaptation

“…Two model species of the Burkholderia group, P. kururiensis strain M130 ( Pk ) and B. vietnamiensis strain LMG10929 ( Bv ), are known to form beneficial and intricate relationships with rice. Both heavily colonize the root surface and have been observed as endophytes ( Mattos et al, 2008 ; King et al, 2019 ). They are potent plant growth promoters which is linked to their ability to transfer fixed atmospheric nitrogen to the plant and to synthetize growth promoting phytohormones ( Trân Van et al, 2000 ; Dias et al, 2019 ).…”

“…japonica cv. Nipponbare plants were cultured as described in King et al (2019) . Briefly, seeds were sterilized using successive 70% ethanol and 3.6% sodium hypochlorite treatments and germinated seedlings were transferred onto sterile perlite in an airtight hydroponic system.…”

Paraburkholderia sp. GD17 improves rice seedling tolerance to salinity

“…In recent years, based on the molecular signatures and phylogenomic analysis, the genus Burkholderia is proposed to be divided into the emended genus Burkholderia only containing the clinically relevant and phytopathogenic organisms and a new genus Paraburkholderia gen. nov. mainly including environmental species (Sawana et al 2014). Interestingly, the colonization of Burkholderia vietnamiensis and Paraburkholderia kururiensis in rice roots caused different (or specific) gene expression, even opposite regulatory patterns such as in jasmonic acid-related network (King et al 2019).…”