Identification and molecular characterization of a b-1,4-endoglucanase gene (Rr-eng-1) from Rotylenchulus reniformis
Wubben, M. J., Ganji, S., & Callahan, F. E. (2010). Identification and molecular characterization of a b-1,4-endoglucanase gene (Rr-eng-1) from Rotylenchulus reniformis. In Melissa Goellner Mitchum (Ed.), Journal of Nematology. The Society of Nematologists. 42(4), 342-351.
b-1,4-endoglucanses, a.k.a. cellulases, are parasitism genes that facilitate root penetration and migration by plant-parasitic
nematodes. Rotylenchulus reniformis is a sedentary semi-endoparasite for which little molecular data has been collected. In this report,
we describe the isolation and characterization of a predicted glycosyl hydrolase family 5 cellulase from R. reniformis that we have
named Rr-eng-1. The Rr-eng-1 cDNA was 1,341 bp long and was comprised of a 19 bp 59-untranslated region (UTR), a 1,245 bp open
reading frame (ORF), and an 80 bp 39-UTR. The Rr-eng-1 genomic sequence was 2,325 bp. Alignment of the cDNA and genomic
sequences revealed seven introns and eight exons for Rr-eng-1. BLASTN analysis showed the Rr-eng-1 cDNA was most homologous to
the Hg-eng-6 mRNA from Heterodera glycines. Southern blot analysis indicated that at least three Rr-eng-1-like sequences were present in
the R. reniformis genome. Translation of the Rr-eng-1 ORF yielded a 414 amino acid peptide (Rr-ENG-1) having an N-terminal signal
sequence for secretion. No cellulose binding module (CBM) was detected in Rr-ENG-1; however, a putative CBM linker sequence
N-terminal to the catalytic domain was present. Rr-ENG-1 was most homologous to Hg-ENG-6 but also shared a number of intron
splice positions with Mi-ENG-2. Quantitative RT-PCR indicated that Rr-eng-1 was highly expressed in the J2 and adult vermiform lifestages
with a sharp decline in expression detected in sedentary females.