Cutting wound ethylene production does not limit the vase life of Acacia holosericea

Abstract

Acacia holosericea stems with attached phyllodes have potential as a cut foliage line in vase displays. However, they have a short vase life. Wounding that occurs during harvest induces ethylene production and promotes the senescence of many plant tissues, but effects on A. holosericea foliage longevity are not known. Wound ethylene was measured from mechanically injured A. holosericea phyllodes and stems at various developmental stages. Modulation of ethylene production was investigated using chemical inhibitor and promoter treatments. The ethylene binding inhibitor silver thiosulfate increased wound ethylene evolution, but did not differentially affect vase life. Vase life was prolonged by nano silver particles and silver nitrate treatments due to the antibacterial effects of these two Ag+ compounds. Treatments with the ethylene synthesis inhibitors α-aminoisobutyric acid and aminoethoxyvinylglycine and with the ethylene binding inhibitor 1-methylcyclopropene had no significant effect on either wound ethylene production or vase life. Treatments with jasmonic acid and methyl jasmonic acid, which can act either synergistically or antagonistically with ethylene, both reduced vase life. Application of exogenous ethylene gas to detached stems induced ethylene production, accelerated senescence, and reduced vase life. However, treatment with the ethylene releasing compound ethephon generally had no effect on vase life. Considered collectively, the results suggest that short longevity of A. holosericea is largely independent of ethylene synthesis at the cutting wound.