An ethylene-related cDNA from ripening apples

Abstract

We report the isolation of a ripening-related apple cDNA which is complementary to a mRNA which may be involved in ethylene production. Poly(A)+ RNA was extracted from cortical tissue of ripe apple fruit (Malus domestica Borkh cv. Golden Delicious) and a cDNA library constructed in the plasmid vector pSPORT. The library was screened with pTOM13, a tomato cDNA clone thought to code for ACC oxidase in that fruit. An apple cDNA clone (pAP4) was isolated and sequenced. The 1182 bp cDNA insert includes an open reading frame of 942 bp, and shows strong homology with reported tomato and avocado sequences, both at the nucleic acid and amino acid levels. The polypeptide has a calculated molecular mass of 35.4 kDa and a calculated pI of 5.15. In apple cortical tissue, expression of pAP4-complementary RNA increased with ethylene production by the fruit during ripening. Expression was also enhanced in both ethylene-treated and wounded fruit.

Differential Expression and Internal Feedback Regulation of 1-Aminocyclopropane-1-Carboxylate Synthase, 1-Aminocyclopropane-1-Carboxylate Oxidase, and Ethylene Receptor Genes in Tomato Fruit during Development and Ripening

“…Although feedback regulation of the ACC oxidase genes has not yet been clarified, there is evidence that accumulation of the transcripts is enhanced with increases in ethylene production and by exogenously applied ethylene in fruits such as tomato (Barry et al, 1996), apple (Ross et al, 1992), melon (Lasserre et al, 1996), banana (Huang et al, 1997), kiwifruit (Whittaker et al, 1997), and pear (Lelievre et al, 1997). In vegetative tissues ACC oxidase mRNA has also been shown to be regulated by ethylene; the transcript for an ACC oxidase gene in excised mung bean hypocotyls was enhanced by exogenous ethylene and suppressed by aminooxyacetic acid, an ACC synthase inhibitor, with a reduction of endogenous ethylene to the basal level (Kim and Yang, 1994).…”

Isolation of a ripening and wound‐induced cDNA from Cucumis melo L. encoding a protein with homology to the ethylene‐forming enzyme

“…The identity of pTOMl3 was confirmed by the expression of ACC oxidase activity in pTOMl3-transformed Saccharomyces cerevisiue cells and Xenopus laevis oocytes (Spanu et al, 1991). cDNA with homology to pTOM13 have also been isolated from avocado (pAVOe3, McGarvey et al, 1990), apple fruit (pAP4, Ross et al, 1992; pAJ32, Dong et al, 1992) and senescent carnation flowers (pSR120, Wang and Woodson, 1991).The ability to extend the storage life and prevent spoilage by inhibiting ethylene biosynthesis in climacteric fruit has already been demonstrated in transgenic tomato plant expressing antisense EFE (Hamilton et al, 1990) and ACC synthase genes. In order to try and extend the storage life of melon fruit by inhibiting ethylene synthesis our initial aim was to isolate an EFE clone from a climacteric melon fruit cDNA library, using the heterologous pTOMl3…”

“…The identity of pTOMl3 was confirmed by the expression of ACC oxidase activity in pTOMl3-transformed Saccharomyces cerevisiue cells and Xenopus laevis oocytes (Spanu et al, 1991). cDNA with homology to pTOM13 have also been isolated from avocado (pAVOe3, McGarvey et al, 1990), apple fruit (pAP4, Ross et al, 1992; pAJ32, Dong et al, 1992) and senescent carnation flowers (pSR120, Wang and Woodson, 1991).…”

A Full-Length cDNA Encoding 1-Aminocyclopropane-1-Carboxylate Synthase from Apple

“…The PAPAS clone was isolated from a library constructed from poly(A+) RNA extracted from ripe apple fruit (M. domestica Borkh. cv Golden Delicious) (Ross et al, 1992). This library was screened with pAAS2, a 1.6-kb partial cDNA clone encoding apple ACC synthase (Dong et al, 1991).…”

“…The extra sequence at the 5' end includes a putative translation start codon at position 100 and sequence encoding nine N-terminal amino acids not present in pAAS2. Relative to pAAS2 there are base substitutions in PAPAS at positions 129 ( lsolated from a cDNA library in pSPORTl (Ross et al, 1992) using pAAS2 Unknown; according to Southern data, gene copy number is low.…”