2 results for Atkinson, RG

  • The Role of Ethylene and Cold Temperature in the Regulation of the Apple POLYGALACTURONASE1 Gene and Fruit Softening

    Tacken, E; Ireland, H; Gunaseelan, K; Karunairetnam, S; Wang, D; Schultz, K; Bowen, J; Atkinson, RG; Johnston, JW; Putterill, Joanna; Hellens, RP; Schaffer, Robert (2010)

    Journal article
    The University of Auckland Library

    Fruit softening in apple (Malus 3 domestica) is associated with an increase in the ripening hormone ethylene. Here, we show that in cv Royal Gala apples that have the ethylene biosynthetic gene ACC OXIDASE1 suppressed, a cold treatment preconditions the apples to soften independently of added ethylene. When a cold treatment is followed by an ethylene treatment, a more rapid softening occurs than in apples that have not had a cold treatment. Apple fruit softening has been associated with the increase in the expression of cell wall hydrolase genes. One such gene, POLYGALACTURONASE1 (PG1), increases in expression both with ethylene and following a cold treatment. Transcriptional regulation of PG1 through the ethylene pathway is likely to be through an ETHYLENE-INSENSITIVE3-like transcription factor, which increases in expression during apple fruit development and transactivates the PG1 promoter in transient assays in the presence of ethylene. A cold-related gene that resembles a COLD BINDING FACTOR (CBF) class of gene also transactivates the PG1 promoter. The transactivation by the CBF-like gene is greatly enhanced by the addition of exogenous ethylene. These observations give a possible molecular mechanism for the cold-and ethylene-regulated control of fruit softening and suggest that either these two pathways act independently and synergistically with each other or cold enhances the ethylene response such that background levels of ethylene in the ethylene-suppressed apples is sufficient to induce fruit softening in apples.

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  • Analysis of expressed sequence tags from Actinidia: Applications of a cross species EST database for gene discovery in the areas of flavor, health, color and ripening

    Crowhurst, RN; Gleave, AP; MacRae, EA; Ampomah-Dwamena, C; Atkinson, RG; Beuning, LL; Bulley, SM; Chagne, D; Marsh, KB; Matich, AJ; Montefiori, M; Newcomb, Richard; Schaffer, Robert; Usadel, B; Allan, Andrew; Boldingh, HL; Bowen, JH; Davy, MW; Eckloff, R; Ferguson, AR; Fraser, LG; Gera, E; Hellens, RP; Janssen, BJ; Klages, K; Lo, KR; MacDiarmid, Robin; Nain, B; McNeilage, MA; Rassam, M; Richardson, AC; Rikkerink, EHA; Ross, GS; Schroder, R; Snowden, KC; Souleyre, EJF; Templeton, Matthew; Walton, EF; Wang, D; Wang, MY; Wang, YY; Wood, M; Wu, RM; Yauk, YK; Laing, WA (2008)

    Journal article
    The University of Auckland Library

    Background: Kiwifruit (Actinidia spp.) are a relatively new, but economically important crop grown in many different parts of the world. Commercial success is driven by the development of new cultivars with novel consumer traits including flavor, appearance, healthful components and convenience. To increase our understanding of the genetic diversity and gene-based control of these key traits in Actinidia, we have produced a collection of 132,577 expressed sequence tags (ESTs). Results: The ESTs were derived mainly from four Actinidia species (A. chinensis, A. deliciosa, A. arguta and A. eriantha) and fell into 41,858 non redundant clusters (18,070 tentative consensus sequences and 23,788 EST singletons). Analysis of flavor and fragrance-related gene families (acyltransferases and carboxylesterases) and pathways (terpenoid biosynthesis) is presented in comparison with a chemical analysis of the compounds present in Actinidia including esters, acids, alcohols and terpenes. ESTs are identified for most genes in color pathways controlling chlorophyll degradation and carotenoid biosynthesis. In the health area, data are presented on the ESTs involved in ascorbic acid and quinic acid biosynthesis showing not only that genes for many of the steps in these pathways are represented in the database, but that genes encoding some critical steps are absent. In the convenience area, genes related to different stages of fruit softening are identified. Conclusion: This large EST resource will allow researchers to undertake the tremendous challenge of understanding the molecular basis of genetic diversity in the Actinidia genus as well as provide an EST resource for comparative fruit genomics. The various bioinformatics analyses we have undertaken demonstrates the extent of coverage of ESTs for genes encoding different biochemical pathways in Actinidia.

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