Nucleotide Sequence of cDNA for Concanavalin A from Canavalia gladiata Seeds

We have determined the nucleotide sequence of Con A cDNA forconcanavalin A (Con A) from Canavalia gladiata using a plasmid(pCONAl) that was isolated previously [Eur. J. Bio-chem. (1988)170: 515-520]. This sequence contains a 870-bp open readingframe, a 63-bp 5'-un-translated region and a 99-bp 3'-untranslatedregion. DNA blot analysis suggested that Con A is encoded bya small gene family. In contrast to the case of canavalin, thenucleotide sequence and the genomic organization of Con A geneare highly conserved between C. gladiata and C. ensifor-mis. (Received August 4, 1988; Accepted November 21, 1988)     

Differential Expression of Genes Involved in the Biosynthesis and Perception of Ethylene during Ripening of Passion Fruit (Passiflora edulis Sims)

An increase in the enzyme activity of 1-aminocyclopropane-1-carboxylicacid (ACC) synthase and ACC oxidase induces the evolution ofethylene during the ripening of passion fruit. A much higherlevel of ethylene is produced in arils than in seeds or peelsduring ripening. The pattern of expression of two ACC synthasegenes (PE-ACS1 and PE-ACS2), one ACC oxidase gene (PE-ACO1),and two ethylene receptor genes (PE-ETR1 and PE-ERS1) revealedthat the expression of these genes is differentially regulated.Expression of PE-ACS1 and PE-ACO1 was enhanced during ripeningand after ethylene treatment. However, prominent expressionof PE-ACS1 was delayed compared to that of PE-ACO1. Much largerquantities of PE-ACS1 mRNA and PE-ACO1 mRNA were seen in arilsthan in seeds; this corresponds well with an increase in theamount of ethylene produced by the plant tissue itself. Thelevel of PE-ACS2 mRNA was detectable in arils of the preclimactericfruit, although it decreased during ripening. These resultssuggest that expression of PE-ACS1 and PE-ACO1 is required toincrease the activity of ethylene biosynthetic enzymes duringripening. The level of expression of PE-ETR1 and PE-ERS1 didnot significantly change over the course of ripening; however,the mRNA levels of PE-ETR1 and PE-ERS1 were much higher in arilsthan in seeds. ⁴Present address: Center forMolecular Genetics Research, Shizuoka University, Shizuoka, 422-8529 Japan.