Articles
STRESS INDICATORS IN PEACH TREES
However, the plant’s response to these factors is thought to be reasonably consistent.
Measurements of some of the physiological indicators of stress in peaches are being made.
1-Aminocyclopropane-1-carboxylic acid (ACC) and 1-(malonylamino)-cyclopropane-1-carboxylic acid (MACC) have been measured as indicators of ethylene production in peach trees growing in nematode infested soil.
The nematodes involved are Criconemella xenoplax and Meloidogyne incognita. M. incognita infected trees were found to have high levels of ACC. MACC and ACC content in leaves sampled monthly indicated that MACC increased linearly throughout the year while ACC levels were higher at the beginning and end of the year.
No significant differences were observed between C. xenoplax infected and control trees.
Additional work is beginning on the effects of stress imposed by the pathogen Xanthomonas campestris pv. pruni. Proteins are being extracted from infected peach tissue with the expectation of finding one or more pathogenesis-related (PR) proteins in infected tissue.
Two extraction methods have been compared to determine the proteins extracted.
Extracts from vacuum-infiltrated tissue contained lower molecular weight proteins when compared to extracts from ground tissue.
PR-proteins isolated by other researchers have had relatively low molecular weights indicating that the vacuum infiltration technique for protein extraction is preferable.