4-Coumarate-CoA Ligase-Like Gene OsAAE3 Negatively Mediates the Rice Blast Resistance, Floret Development and Lignin Biosynthesis.

ABSTRACT: Although adenosine monophosphate (AMP) binding domain is widely distributed in multiple plant species, detailed molecular functions of AMP binding proteins (AMPBPs) in plant development and plant-pathogen interaction remain unclear. In the present study, we identified an AMPBP OsAAE3 from a previous analysis of early responsive genes in rice during Magnaporthe oryzae infection. OsAAE3 is a homolog of Arabidopsis AAE3 in rice, which encodes a 4-coumarate-Co-A ligase (4CL) like protein. A phylogenetic analysis showed that OsAAE3 was most likely 4CL-like 10 in an independent group. OsAAE3 was localized to cytoplasm, and it could be expressed in various tissues. Histochemical staining of transgenic plants carrying OsAAE3 promoter-driven GUS (?-glucuronidase) reporter gene suggested that OsAAE3 was expressed in all tissues of rice. Furthermore, OsAAE3-OX plants showed increased susceptibility to M. Oryzae, and this finding was attributable to decreased expression of pathogen-related 1a (PR1) and low level of peroxidase (POD) activity. Moreover, OsAAE3 over-expression resulted in increased content of H2O2, leading to programmed cell-death induced by reactive oxygen species (ROS). In addition, OsAAE3 over-expression repressed the floret development, exhibiting dramatically twisted glume and decreased fertility rate of anther. Meanwhile, the expressions of lignin biosynthesis genes were significantly decreased in OsAAE3-OX plants, thereby leading to reduced lignin content. Taken together, OsAAE3 functioned as a negative regulator in rice blast resistance, floret development, and lignin biosynthesis. Our findings further expanded the knowledge in functions of AMBPs in plant floret development and the regulation of rice-fungus interaction.

SUBMITTER: Liu H 

PROVIDER: S-EPMC5222848 | biostudies-literature | 2016

REPOSITORIES: biostudies-literature