title: Novel jasmonate amino acid conjugates in Asparagus officinalis during harvest-induced and natural foliar senescence.
abstract: Five jasmonates, including novel tryptophan conjugates of jasmonic acid and dihydrojasmonic acid, were identified in extracts from spears of Asparagus officinalis L. by electrospray tandem mass spectrometry. Spears were harvested and were held dry or with bases immersed in water. The concentrations of jasmonic acid, dihydrojasmonic acid, their tryptophan conjugates, cucurbic acid and methyl jasmonate, were measured by ELISA in spears in the 10 d following harvest. A transient increase that occurred in all spear tips immediately following harvest in the concentration of jasmonates can be attributed to a wounding response. A second increase in the concentration of jasmonates occurred from 7 d after harvest but only in dry-treated spear tips indicating that jasmonates may have accumulated in response to water stress. Jasmonate levels were also monitored during natural foliar senescence. Increased levels of jasmonates occurred after the onset of senescence, implicating them as a consequence rather than a cause of senescence.
authors: Institute of Molecular BioSciences, Massey University, Private Bag 11222, Palmerston North, New Zealand New Zealand Institute for Crop & Food Research Limited, Private Bag 11600, Palmerston North, New Zealand Division of Retrovirology, NIBSC, Blanche Lane, South Mimms, Hertfordshire EN6 3QG, UK.
authors: Nigel E
authors: NE
authors: Gapper
authors: Gill E
authors: GE
authors: Norris
authors: Sean F
authors: SF
authors: Clarke
authors: Ross E
authors: RE
authors: Lill
authors: Paula E
authors: PE
authors: Jameson