Bean Ribonuclease‐Like Pathogenesis‐Related Protein Genes (Ypr10) Display Complex Patterns of Developmental, Dark‐Induced and Exogenous‐Stimulus‐Dependent Expression

Abstract

The intracellular pathogenesis-related (PR) proteins of common bean (Phaseolus vulgaris L.) are encoded by a highly polymorphic family of at least 20 genes. One member, the Ypr10*c gene, has been isolated and characterised. The deduced amino acid sequence of the encoded protein, PR-10, exhibits similarities to tree-pollen allergens, to food allergens from celery and apple and to ginseng ribonuclease peptide sequences. We show by RNA blot analysis that the Ypr10 gene family, including Ypr10*c, is strongly expressed in bean roots. In leaves Ypr10 transcript levels are low in young and mature stages but are elevated during senescence and in diseased states. Dark treatment of leaves causes strong induction of Ypr10 transcripts, which is reversible by light, and diurnal rhythms of transcript accumulation during the night are observed. Ypr10 genes are responsive to external stimuli related to pathogen-defence such as glutathione or salicylic acid. Transcriptional activity of a Ypr10*c promoter-beta-glucuronidase fusion gene in transgenic tobacco was observed in roots, in developing xylem and phloem of stems, and in the blade of senescent leaves, with highest levels at the onset of senescence. The most striking characteristic of developmental expression was the specific localisation of beta-glucuronidase activity in the transmitting tract of styles in flowers at anthesis. Feeding of various pathogen-related and stress-related stimuli to young tobacco leaves led to accumulation of GUS activity in leaf blades. We identify considerable spatio-temporal similarities between reported expression patterns of Ypr10 genes and ribonuclease genes, which, together with the significant sequence similarity to the ginseng ribonuclease, support the hypothesis of a ribonuclease function for PR-10 proteins and allow the prediction of possible biological roles.

An Ethylene-Induced Regulatory Module Delays Flower Senescence by Regulating Cytokinin Content

“…In bean (Phaseolus vulgaris), the transcript levels of the PR-10 protein Ypr10 were reported to increase at the onset of leaf senescence (Walter et al, 1996), and in yellow lupine, the expression of the PR-10 gene LlPR10.1A was induced in senescent leaves (Sikorski et al, 1999). Here, we showed that in rose, the transcript levels of several PR10 members also accumulated during flower senescence (Supplemental Fig.…”

Proteomic Study of Low-Temperature Responses in Strawberry Cultivars (Fragaria×ananassa) That Differ in Cold Tolerance

“…b-1,3-Glucanases comprise a large and highly complex gene family involved in pathogen defense, as well as a broad range of other biological processes. YPR10 belongs to a group of pathogenesis-related proteins whose function is largely unknown although functions have been speculated to include RNase and proteinase activities (Walter et al, 1996). In the cold-tolerant 'Jonsok', two different b-1,3-glucanase proteins as well as the pathogen-responsive protein, YPR10 were identified.…”

Physical and transcript map of the region between D6S264 and D6S149 on chromosome 6q27, the minimal region of allele loss in sporadic epithelial ovarian cancer

“…Once regarded as ubiquitous`housekeeping enzymes', they are now recognized to control processes ranging from splicing to organogenesis (Schein, 1997). It has been known that both plant and mammalian RNAses are produced in response to stress (Ye and Droste, 1996), Oncogene Chromosome 6q27 ovarian cancer tumour suppressor gene Y Liu et al and pathogenic agents, particularly viruses (Walter et al, 1996). RNAse active in greenhouse wheat increases during senescence, as does RNAse activity in human tissues (Francesconi et al, 1984).…”