ศูนย์นวัตกรรมเทคโนโลยีหลังการเก็บเกี่ยว

Involvement of ethylene biosynthesis and action in regulation of the gravitropic response of cut flowers.

Philosoph-Hadas, S.; Friedman, H.; Berkovitz-Simantov, R.; Rosenberger, I.; Woltering, E. J.; Halevy, A. H.; Meir, S.;

Biology and biotechnology of the plant hormone ethylene II. Proceedings of the EU-TMR-Euroconference Symposium, Thira (Santorini), Greece, 5-8 September, 1998. Year: 1999 Pages: 151-156 Ref: 16 ref.

1999

บทคัดย่อ

Placing cut Antirrhinum majus spikes horizontally induced elevated ethylene production rates. The imposition of curvature was preceded (2 h after gravistimulation) by an asymmetrical distribution of ethylene between lower and upper longitudinally halved stem sections, in favour of the lower halves. A corresponding gradient of free IAA was detected only 30 min after gravistimulation. This IAA gradient was rapidly reversed after 1-24 h of gravistimulation, showing higher IAA levels in the upper stem halves. Additionally, one ACC synthase (ACS) gene, isolated from the bending zone of horizontal spikes, was apparently not expressed in IAA-treated stems. Thus, the gravity-induced ethylene asymmetry did not reflect an asymmetrical distribution of free IAA, but rather possibly exhibited a stress response imposed by change of stem orientation. Abolishing the ethylene gradient across the stem by applying various ethylene inhibitors (CoCl2, aminoethoxyvinyl-glycine (AVG), silver thiosulfate (STS), 2,5-nor

bornadiene (NBD) or 1-methylcyclopropene (1-MCP)), by exposure to ethylene (1-10 micro l/litre), or by using Ca2+ antagonists (LaCl3, EGTA, 1,2-bis (2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid (BAPTA) or trans-1,2-cyclohexane dinitro-N,N,N',N'-tetraacetic acid (CDTA)), significantly inhibited curvature. This indicated that the ethylene gradient was correlated with bending, and suggested a role for ethylene in mediating the progress of the gravitropic response.