Gummosis in grape hyacinth (Muscari armeniacum) bulbs: hormonal regulation and chemical composition of gums

Abstract

The purpose of this study was to investigate the hormonal regulation of gummosis in grape hyacinth (Muscari armeniacum) bulbs, focusing especially on the chemical composition of the gums. The application of ethephon (2-chloroethylphosphonic acid), an ethylene-releasing compound, at 1% and 2% (w/w) in lanolin as well as ethylene induced gummosis in the bulbs within several days. Methyl jasmonate (JA-Me, 0.1-2% in lanolin) alone had no effect on gummosis. However, simultaneous application of JA-Me and ethephon led to extreme stimulation of ethephon-induced gummosis. Ethephon-induced gummosis in the bulbs depended on the maturation stage of the bulbs, increasing from April to July, but decreasing from August to September. Regardless of the presence of JA-Me, the application of ethephon to the inflorescence axis of grape hyacinths did not induce gummosis. Gel permeation chromatography analysis revealed that gums were homogenous polysaccharides with an average molecular mass of ca. 8.3 kDa. Analysis of the sugar composition of the gums after hydrolysis revealed that the molar ratio of Rha:Ara:Gal:GalA:GlcA was 25:10:40:7:15. These results suggest that principal factors of gummosis as well as the chemical composition of gums differ between species of bulbous plants.

Effects of pre‐ and post‐treatment with ethephon on gum formation of peach gummosis caused by Lasiodiplodia theobromae

“…Gummosis, which is a common response to pathogen infection, wounding or insect attack, is the process of gum accumulation and exudation in some plant species, such as tulip, grape hyacinth, cashew and the stone fruit tree species of Rosaceae (Saniewski et al ., ; Cysne et al ., ; Miyamoto et al ., ). Peach gummosis, caused by Botryosphaeria spp.…”

“…Pathogen attack triggers complex signalling cascades regulated by signalling molecules, such as salicylic acid (SA), jasmonic acid (JA) and ethylene (ET) (Glazebrook, ). Hormonal regulation of gummosis has been reported in stone fruit trees of Rosaceae and other genera, which suggests that ET, JA and methyl jasmonate (MeJA) are essential factors in the interaction with gummosis (Saniewski et al ., ; Skrzypek et al ., ; Miyamoto et al ., ). MeJA induces gum increase in peach and tulip shoots, and interacts with ethylene (Saniewski et al ., ,b).…”

Ethephon: a tool to boost gum arabic production from Acacia senegal and to enhance gummosis processes

“…It increases both latex metabolism and latex flow and is a wellknown tool in rubber tapping systems (D'Auzac et al 1997;Lacote et al 2010). Ethephon has been successfully tested in several gum or resin producing species (Greenwood and Morey 1979;Nair et al 1995;Miyamoto et al 2010). However, there so far has been only one study with A. senegal.…”

Influence factors and gene expression patterns during MeJa-induced gummosis in peach

“…Gummosis is a process involving the accumulation and exudation of gum or sap from tree trunks, branches, and fruits in some plant species Cysne, 2010;Miyamoto, 2010). Gummosis is especially common in stone-fruit trees such as peach, cherry, and plum (Boothby, 1983;Butler, 1911;Bukovac and Olien, 1982).…”

“…Jasmonates [jasmonic acid (JA), methyl jasmonate (MeJa) and their related compounds] have been demonstrated to play important roles in regulating plant growth and development. Hormonal regulation of gummosis has been reported in many stone fruit trees, which suggests that jasmonates and ethylene are essential factors in the interaction with gummosis (Saniewski, 2004c;Miyamoto, 2010). Jasmonates have been found to induce gums in various species of stone-fruit trees such as plum shoots and fruits, and the shoots of peach, cherry and apricot (Saniewski et al, 1998a;2004ab;Ueda et al, 2003).…”