Do seed VLCFAs trigger spongy tissue formation in Alphonso mango by inducing germination.

Spongy tissue is a physiological disorder in Alphonso mango caused by the inception of germination-associated events during fruit maturation on the tree, rendering the fruit inedible. Inter-fruit competition during active fruit growth is a major contributing factor for the disorder which leads to reduced fat content in spongy tissue affected fruits. This study was, therefore, carried out to determine the possible association between seed fats and ST formation. The study of the fat content during fruit growth showed that it increased gradually from 40% fruit maturity. At 70% maturity, however, there was a sudden increase of fat content of whole fruit, leading to acute competition and resulting in differential allocation of resources among developing fruits. As a result, the seed in spongy-tissue-affected mature ripe fruit showed a marked drop in the levels of fats and the two very long chain fatty acids (VLCFAs), tetracosanoic acid and hexacosanoic acid together with an increase of linolenic acid and a fall in oleic acid contents, which are known to be key determinants for the initiation of pre-germination events in seed. Subsequently, a rise in the level of cytokinin and gibberellins in ST seed associated with a fall in abscisic acid level clearly signalled the onset of germination. Concurrently, a significant reduction in the ratio of linolenic acid/linoleic acid in pulp led to the loss of membrane integrity, cell death and the eventual formation of spongy tissue. Based on the above, it is concluded that a significant reduction in the biosynthesis of VLCFAs in seeds during fruit growth might trigger pre-germination events followed by a cascade of biochemical changes in the pulp, leading to lipid peroxidation and membrane injury in pulp culminating in ST development. Thus, this study presents crucial experimental evidence to highlight the critical role played by VLCFAs in inducing ST formation in Alphonso mango during the pre-harvest phase of fruit growth.

Clinical profile of adrenoleukodysrophy.

X-linked Adrenoleukodystrophy (ALD) is the most common of the peroxisomal disorder and is associated with functional defect of the very long chain fatty acid (VLCFA) oxidation leading to the accumulation of VLCFA in the white matter and adrenal cortex. Retrospective evaluation of medical records of ALD patients were carried out. In all the 5 patients the duration of the symptoms varied from 1-7 years. Most of them presented with Addisonian crisis (4/5) and hyperpigmentation (5/5), white half of them (3/5) had neurological symptoms. All patients had biochemical evidence of the adrenal insufficiency. All siblings of patients should be screened for the possibility of ALD with VLCFA.