Graft Transmissible Agents Affect Membrane Fatty Acid Saturation during Dormancy Release in Peach

Abstract

<jats:p>Peach [<jats:italic>Prunus persica</jats:italic> (L.) Batsch (Peach Group)] trees infected with peach latent mosaic viroid (PLMVd) have been associated with phenological changes including delay in bloom, reduced shoot vigor, and early autumn defoliation. In order to further characterize the changes occurring in trees inoculated with PLMVd, total fatty acid content was measured for floral buds during release from dormancy in `Coronet' peach trees. Palmitic (16:0), stearic (18:0), oleic (18:1), linoleic (18:2), and linolenic (18:3) acids were the major fatty acids in dormant and releasing peach buds of both control and PLMVd-inoculated (VI) trees. The degree of unsaturation increased immediately following release from dormancy in both the control and VI trees. However, desaturation of linoleic acid to linolenic acid was significantly inhibited in VI trees, which was accompanied by a concomitant delay in the resumption of growth. The disparity between the control and VI trees in the progression of increased fatty acid unsaturation continued through petal fall. The presence of PLMVd in `Coronet' peach trees slowed membrane fatty acid desaturation during release from dormancy and suggested that metabolic pathways involving fatty acid desaturation were linked to the delayed phenology of the VI trees.</jats:p>

Ethephon-Mediated Bloom Delay in Peach Is Associated With Alterations in Reactive Oxygen Species, Antioxidants, and Carbohydrate Metabolism During Dormancy

“…Fatty acid unsaturation plays a central role in dormancy release ( Norman et al, 1991 ; Erez et al, 1997 ; Gabay et al, 2019 ). For example, inhibiting the unsaturation of fatty acids, especially the conversion of linoleic acid (C18:2) to α-linolenic acid (C18:3), delayed bud dormancy release in peach ( Gibson et al, 2004 ). Also, the exogenous application of α-linolenic acid was found to promote dormancy break in Japanese pear ( Sakamoto et al, 2010 ).…”

From endodormancy to ecodormancy: the transcriptional landscape of apple floral buds

“…This compound has been found to induce bud break in Japanese pear when applied (Sakamoto et al, 2010). Furthermore, inoculating peach plants with the peach latent viroid has been shown to inhibit fatty acid unsaturation, particularly the conversion of linoleic acid (C18:2) to a-linolenic acid (C18:3), resulting in delayed dormancy release (Gibson et al, 2004).These findings collectively suggest that linolenic acid accumulation and its oxylipin metabolites, including JA, may play a role in regulating dormancy release and flowering. In the current study, we discovered that the linoleate 13S-lipoxygenase transcripts (MdLOX-2.1 and MdLOX-5) were downregulated in 'Honeycrisp' compared to 'Cripps Pink' during ecodormancy.…”