Identification of the soybean HyPRP family and specific gene response to Asian soybean rust disease

Abstract

Soybean [Glycine max (L.) Merril], one of the most important crop species in the world, is very susceptible to abiotic and biotic stress. Soybean plants have developed a variety of molecular mechanisms that help them survive stressful conditions. Hybrid proline-rich proteins (HyPRPs) constitute a family of cell-wall proteins with a variable N-terminal domain and conserved C-terminal domain that is phylogenetically related to non-specific lipid transfer proteins. Members of the HyPRP family are involved in basic cellular processes and their expression and activity are modulated by environmental factors. In this study, microarray analysis and real time RT-qPCR were used to identify putative HyPRP genes in the soybean genome and to assess their expression in different plant tissues. Some of the genes were also analyzed by time-course real time RT-qPCR in response to infection by Phakopsora pachyrhizi, the causal agent of Asian soybean rust disease. Our findings indicate that the time of induction of a defense pathway is crucial in triggering the soybean resistance response to P. pachyrhizi. This is the first study to identify the soybean HyPRP group B family and to analyze disease-responsive GmHyPRP during infection by P. pachyrhizi.

RNAi-based functional elucidation of PtrPRP, a gene encoding a hybrid proline rich protein, in cold tolerance of Poncirus trifoliata

“…Expression of PRPs was shown to be associated with development of various tissues and exhibited temporal and spatial expression patterns ( Vignols et al, 1999 ; Gothandam et al, 2010 ; Neto et al, 2013 ). Transcripts of ZmHyPRP from maize were specifically observed in the immature embryos ( Josè-Estanyol et al, 1992 ), while a HyPRP gene of strawberry was exclusively found in mature fruits ( Blanco-Portales et al, 2004 ).…”

“…SbPRP2 was the predominant form of transcripts in the apical hypocotyl and young suspension culture cells, while the transcripts of SbPRP3 accumulated mainly in aerial parts, especially in leaves. In a recent study, Neto et al (2013) expanded the soybean HyPRP proteins to 35 members, which exhibited variable expression patterns in six vegetative organs, root, and root tip, nodule, leaves, green pods, flower, and apical meristem. Some of them were not detected in any tissue, while others were expressed in specific organs.…”

“…Hybrid proline-rich proteins (HyPRPs) are a subset of proline-rich proteins (PRPs) specific to seed plants; however, they do not contain the domain typical of PRPs ( Josè-Estanyol et al, 2004 ; Priyanka et al, 2010 ; Xu et al, 2011 ). Based on the position and number of cysteine residues at C terminal, HrPRPs can be categorized into two major groups, in which Class A has 4–6 cysteine residues, while Class B contains a conserved eight-cysteine-motif (8 CM) at C terminal, a repetitive proline-rich N-terminal domain (PRD) and a signal peptide in front of the PRD ( Josè-Estanyol and Puigdomènech, 2000 ; Josè-Estanyol et al, 2004 ; Battaglia et al, 2007 ; Dvořáková et al, 2007 ; Neto et al, 2013 ). HyPRPs have been suggested to play important biological roles in various processes, including plant cell elongation, ontogeny, and morphogenesis of different organs, defenses against viral or fungal pathogens ( He et al, 2002 ; Holk et al, 2002 ; Dvořáková et al, 2012 ).…”

Pigeonpea Hybrid-Proline-Rich Protein (CcHyPRP) Confers Biotic and Abiotic Stress Tolerance in Transgenic Rice

“…The increased endochitinase levels found in transgenics are plausibly due to the involvement of Cc HyPRP as one of the components in the defense signaling cascade. In soybean, a HyPRP ( Gm HyPRP) gene showed higher expression levels in response to the pathogenic fungus ( Phakopsora pachyrhizi) which causes Asian soybean rust disease (Neto et al, 2013 ). Jung et al ( 2009 ) reported the involvement of A. thaliana HyPRP (AZI1) in plant defense against the Pseudomonas syringae .…”

HyPRP1 performs a role in negatively regulating cotton resistance to V. dahliae via the thickening of cell walls and ROS accumulation

“…For example, CaHyPRP1 performs distinct dual roles as a negative regulator of basal defense and in the positive regulation of cell death in Capsicum annuum against Xanthomonas campestris [ 3 ]. GmHyPRP is involved in triggering the soybean resistance response to Phakopsora pachyrhizi [ 4 ]. The HyPRP gene EARLI1 (Early Arabidopsis Aluminum Induced 1) is induced in Arabidopsis by low temperature and salt stress [ 5 ].…”