Publications (4)18.37 Total impact
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Article: Expression of auxin-binding protein1 during plum fruit ontogeny supports the potential role of auxin in initiating and enhancing climacteric ripening.
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ABSTRACT: Auxin-binding protein1 (ABP1) is an active element involved in auxin signaling and plays critical roles in auxin-mediated plant development. Here, we report the isolation and characterization of a putative sequence from Prunus salicina L., designated PslABP1. The expected protein exhibits a similar molecular structure to that of well-characterized maize-ABP1; however, PslABP1 displays more sequence polarity in the active-binding site due to substitution of some crucial amino-acid residues predicted to be involved in auxin-binding. Further, PslABP1 expression was assessed throughout fruit ontogeny to determine its role in fruit development. Comparing the expression data with the physiological aspects that characterize fruit-development stages indicates that PslABP1 up-regulation is usually associated with the signature events that are triggered in an auxin-dependent manner such as floral induction, fruit initiation, embryogenesis, and cell division and elongation. However, the diversity in PslABP1 expression profile during the ripening process of early and late plum cultivars seems to be due to the variability of endogenous auxin levels among the two cultivars, which consequently can change the levels of autocatalytic ethylene available for the fruit to co-ordinate ripening. The effect of auxin on stimulating ethylene production and in regulating PslABP1 was investigated. Our data suggest that auxin is involved in the transition of the mature green fruit into the ripening phase and in enhancing the ripening process in both auxin- and ethylene-dependent manners thereafter.Plant Cell Reports 06/2012; 31(10):1911-21. · 2.27 Impact Factor -
Article: Identification and genetic characterization of a gibberellin 2-oxidase gene that controls tree stature and reproductive growth in plum.
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ABSTRACT: Several dwarf plum genotypes (Prunus salicina L.), due to deficiency of unknown gibberellin (GA) signalling, were identified. A cDNA encoding GA 2-oxidase (PslGA2ox), the major gibberellin catabolic enzyme in plants, was cloned and used to screen the GA-deficient hybrids. This resulted in the identification of a dwarf plum hybrid, designated as DGO24, that exhibits a markedly elevated PslGA2ox signal. Grafting 'Early Golden' (EG), a commercial plum cultivar, on DGO24 (EG/D) enhanced PslGA2ox accumulation in the scion part and generated trees of compact stature. Assessment of active GAs in such trees revealed that DGO24 and EG/D accumulated relatively much lower quantities of main bioactive GAs (GA(1) and GA(4)) than control trees (EG/M). Moreover, the physiological function of PslGA2ox was studied by determining the molecular and developmental consequences due to ectopic expression in Arabidopsis. Among several lines, two groups of homozygous transgenics that exhibited contrasting phenotypes were identified. Group-1 displayed a dwarf growth pattern typical of mutants with a GA deficiency including smaller leaves, shorter stems, and delay in the development of reproductive events. In contrast, Group-2 exhibited a 'GA overdose' phenotype as all the plants showed elongated growth, a typical response to GA application, even under limited GA conditions, potentially due to co-suppression of closely related Arabidopsis homologous. The studies reveal the possibility of utilizing PslGA2ox as a marker for developing size-controlling rootstocks in Prunus.Journal of Experimental Botany 11/2011; 63(3):1225-39. · 5.36 Impact Factor -
Article: Regulation of two germin-like protein genes during plum fruit development.
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ABSTRACT: Germin-like proteins (GLPs) have several proposed roles in plant development and defence. Two novel genes (Ps-GLP1 and 2) encoding germin-like protein were isolated from plum (Prunus salicina). Their regulation was studied throughout fruit development and during ripening of early and late cultivars. These two genes exhibited similar expression patterns throughout the various stages of fruit development excluding two important stages, pit hardening (S2) and fruit ripening (S4). During fruit development until the ripening phase, the accumulation of both Ps-GLPs is related to the evolution of auxin. However, during the S2 stage only Ps-GLP1 is induced and this could putatively be in a H(2)O(2)-dependent manner. On the other hand, the diversity in the Ps-GLPs accumulation profile during the ripening process seems to be putatively due to the variability of endogenous auxin levels among the two plum cultivars, which consequently change the levels of autocatalytic ethylene available for the fruit to co-ordinate ripening. The effect of auxin on stimulating ethylene production and in regulating Ps-GLPs transcripts was also investigated. These data, supported by their localization in the extracellular matrix, suggest that auxin is somehow involved in the regulation of both transcripts throughout fruit development and ripening.Journal of Experimental Botany 03/2010; 61(6):1761-70. · 5.36 Impact Factor -
Article: Molecular characterization of seven genes encoding ethylene-responsive transcriptional factors during plum fruit development and ripening.
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ABSTRACT: Seven ERF cDNAs were cloned from two Japanese plum (Prunus salicina L.) cultivars, 'Early Golden' (EG) and 'Shiro' (SH). Based on the sequence characterization, these Ps-ERFs could be classified into three of the four known ERF families. Their predicted amino acid sequences exhibited similarities to ERFs from other plant species. Functional nuclear localization signal analyses of two Ps-ERF proteins (Ps-ERF1a and -1b) were carried out using confocal microscopy. Expression analyses of Ps-ERF mRNAs were studied in the two plum cultivars in order to determine the role of this gene family in fruit development and ripening. The seven Ps-ERFs displayed differential expression pattern and levels throughout the various stages of flower and fruit development. The diversity in Ps-ERFs accumulation was largely due to the differences in their responses to the levels of ethylene production. However, other plant hormones such as cytokinin and auxin, which accumulate strongly throughout the various developmental stages, also influence the Ps-ERFs expression. The effect of the plant hormones, gibberellin, cytokinin, auxin, and ethylene in regulating the different Ps-ERF transcripts was investigated. A model was proposed in which the role played by the plant hormone auxin is as important as that of ethylene in initiating and determining the date and rate of ripening in Japanese plums.Journal of Experimental Botany 03/2009; 60(3):907-22. · 5.36 Impact Factor
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Institutions
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2009–2012
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University of Guelph
- Department of Plant Agriculture
Guelph, Ontario, Canada
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