Isolation of nine Phytophthora capsici pectin methylesterase genes which are differentially expressed in various plant species

Abstract

Phytophthora capsici causes damage on many plants species, and secretes various pectin methylesterases during all stages of infection. We identified nine Pme genes (Pcpme 1-9) from a genomic library of highly virulent P. capsici strain SD33 and further analyzed the expression pattern of nine genes on three hosts: pepper, tomato, and cucumber using qRT-PCR during all stages of infection. All nine genes were found to be differentially expressed in three host species in the course of P. capsici interaction. The expression levels of the respective genes increased from 1 to 7 dpi in pepper, while most genes presented a decreasing trend of expression from 1 to 5 dpi in tomato fruits. However, in both fruits peaks were reached at 7 dpi. In cucumber fruits, each gene showed minor expression levels from 1 to 3 dpi, exhibited definite peaks at 5 dpi, and then decreased from 5 to 7 dpi. Thus, evidence from our studies of Pcpme gene expression in different plants at a rang of time points suggests that the late stages of infection may represent the most critical time for P. capsici to successfully express or/and secret PMEs.

The Pectin Methylesterase Gene Complement of Phytophthora sojae: Structural and Functional Analyses, and the Evolutionary Relationships with Its Oomycete Homologs

“…A previous study in Phytophthora infestans , a pathogen of potato and tomato, revealed that PME expression in that species is highest in the first day of infection [ 15 ]. In contrast, analysis of PME expression in Phytophthora capsici revealed that highest levels of expression occur after one week of infection [ 16 ]. Life cycle differences among P .…”

Structure and Properties of a Non-processive, Salt-requiring, and Acidophilic Pectin Methylesterase from Aspergillus niger Provide Insights into the Key Determinants of Processivity Control

“…1). As well as being ubiquitous in plants, and frequently manifesting in a staggering number of isoforms (more than 66 for Arabidopsis thaliana) (8,10), PMEs are found in phytopathogenic bacteria and fungi (17)(18)(19)(20)(21)(22)(23)(24)(25)(26) and in Archaea (especially Halobacteriaceae (27)), and they have also been observed in the genomes of several phytophagous insects (28 -30) and in human gut microflora (31). Recently, plant pollen PMEs have been identified as a key human allergen (32,33).…”

Purification of p47f, a Necrosis‐Inducing Protein Fraction from the Secretome of Phytophthora capsici

“…The extracellular group includes secreted effectors such as well-known protease inhibitors, cysteine proteases, subtilisin-like proteases and aspartic proteases, which act on targets located in the extracellular space (Kamoun 2006;van der Hoorn and Kamoun 2008), as well as the 18 recently described necrosis-inducing Phytophthora proteins (PcNpp) and the nine pectin methylesterases (Pme) identified in P. capsici strain SD33 Li et al 2011).…”

“…It has been proposed that secreted necrosis-promoting proteins (NPPs) in P. capsici contribute to the transition from biotrophy to necrotrophy; twelve PcNpp genes are expressed in P. capsici during infection, but their functional roles in the virulence of the oomycete remain unclear . Additionally, pectin methylesterase (PcPme) genes are also expressed during infection, and it has been shown that the exposure of plant tissue to PcPme proteins results in collapsing of the tissue and cell death (Lamour et al 2012;Li et al 2011).…”