title: Effect of pectic oligomers on physiological responses of chilling injury in discs excised from zucchini (Cucurbita pepo L.).
abstract: The effect of pectic oligomers (OG) on ethylene biosynthesis, electrolyte leakage (EL), and CO(2) production was studied in discs excised from zucchini fruit (Cucurbita pepo L.) and stored at 20 or 2.5 degrees C. At 20 degrees C, OG enhanced ethylene biosynthesis and had a transient effect on decreasing EL, but showed little effect on respiratory rate; both the amount and size of the oligomer were important in changing both ethylene synthesis and EL. At 2.5 degrees C, OG increased both ethylene biosynthesis and respiratory rate with a maximum effect at 100 microg of oligomer and peaking at 6 h; shorter oligomers demonstrated an even greater effect on ethylene biosynthesis, but differences were smaller in respiratory rate. EL at 2.5 degrees C was affected most by 1 microg of OG and by monomeric galacturonic acid, with transient increases that peaked at 8 h. We suggest a signaling role for OG in the early steps of cold acclimation or chilling injury.
authors.affiliation: Universidad Autónoma de Chihuahua, Facultad de Ciencias Químicas, Ciudad Universitaria s/n, Apdo. Postal 1542-C, Chihuahua, Chih, México.
authors.forename: René R
authors.initials: RR
authors.lastname: Balandrán-Quintana
authors.forename: Ana Ma
authors.initials: AM
authors.lastname: Mendoza-Wilson
authors.forename: Gerardo
authors.initials: G
authors.lastname: Alvarez-Manilla
authors.forename: Carl W
authors.initials: CW
authors.lastname: Bergmann
authors.forename: Irasema
authors.initials: I
authors.lastname: Vargas-Arispuro
authors.forename: Miguel Angel
authors.initials: MA
authors.lastname: Martínez-Téllez
mesh_terms: D002245:Carbon Dioxide / Q000378:metabolism; D002847:Chromatography, Agarose; D003080:Cold Temperature; D028464:Cucurbita / Q000737:chemistry*; D004573:Electrolytes / Q000378:metabolism; D005030:Ethylenes / Q000096:biosynthesis / Q000378:metabolism; D006603:Hexuronic Acids / Q000494:pharmacology; D013696:Temperature; D013997:Time Factors
chemical_list: D004573:Electrolytes; D005030:Ethylenes; D006603:Hexuronic Acids; D002245:Carbon Dioxide; C007819:galacturonic acid