Structure andexpression ofanethylene-related mRNA fromtomato

MessengerRNAs homologousto a cDNA clone(pTOM 13) derivedfrom a ripe -tomato -specific cDNA library areexpressed during tomatofruit ripening andafter the woundingof leafandgreenfruit material. Bothresponses involve thesynthesis ofthe hormoneethylene. Accumulation ofthepTOM 13-homologous RNA during ripening israpid andsustained, andreaches itsmaximumlevel inorangefruit. Following mechanical wounding oftomatoleaves a pTOM 13-homologous RNA showsrapidinduction within 30 minutes, whichoccursbefore maximal ethylene evolution (2-3h). ThisRNA alsoaccumulates following thewounding ofgreentomatofruit. Northern blotanalysis ofpoly(A) + RNA indicates that thelength ofthemRNA isabout1400nucleotides. Nucleotide sequence analysis showedthe cDNA insert tocontain thecomplete coding region ofthepTOM 13protein (33.5kD) and an unusual 5'structure oftendT-nucleotides. Hybridisation ofthepTOM 13cDNA insert to Southern blotsof tomatoDNA indicates thepresence of onlya smallnumberof homologous sequences inthetomatogenome.