THE DISTRIBUTION OF ACETYLCHOLINE IN THE MALAYAN JACK‐FRUIT PLANT, ARTOCARPUS INTEGRA

Abstract

The distribution of acetylcholine in the seeds and leaves of the Malayan Jack-fruit plant, Artocarpus integra, has been studied with the view to obtaining evidence for the site of its formation. The terminal growing leaves on the side branches had a very high concentration of acetylcholine (770 /Ag./g.), while the acetylcholine content of the other leaves on the same branch progressively decreased with age. The total amount of acetylcholine stored in the terminal growing leaves was only 42 ptg., but in the second leaves which had grown nearly to their full size it was 540 ,ug. From the third leaves, the amount of acetylcholine stored gradually decreased. The midribs and the secondary veins of the leaves when combined had a higher concentration of acetylcholine than had the blades. The acetylcholine concentration of the pith of the stem was 4.2 times higher than that of the cortex-phloem layer while that of the xylem layer was the lowest; in the root the pith had a value only one-seventh of the cortex. The younger part of the pith and the cortex-phloem layers of the stem contained more acetylcholine than the older parts. These findings support the view that the acetylcholine is synthesized in the growing leaves. An unusual lenticel-like structure in the cortex layer of the root contained more acetylcholine than the surrounding tissue.

The effect of light on the level of acetylcholine in seedlings of the wild-type and phytochrome mutants of tomato (Lycopersicon esculentum Mill.)

“…2). Lin (1957) and Jaffe (1970) obtained similar results in Artocarpus integra and in Phaseolus aureus. In beans the highest concentration of ACh occurred in apical buds, in roots tops and in the young cotyledons.…”

Isolation, purification and identification of acetylcholine in Pharbitis nil seedlings

“…Its presence was found in all the organs of the examined plant: seeds, shoot apex, cotyledons, leaves, shoots and roots (Figure). Similarly as in case of other plant species (Lin 1957, Jaffe 1970 also in P nil the existence of the gradient of ACh concentrations in different organs was found. The highest level of the investigated substance was noted in the youngest growing parts.…”

Evidence for the Regulation of Phytochrome-mediated Processes in Bean Roots by the Neurohumor, Acetylcholine

“…16A). Atropine changed the amplitude but not the rate of red light-induced adhesion (Table VII) (1), tissues of Girardinia helerophylla (27), leaves, seeds, and roots of Amsonia angustifolia (32), tissues of Digitalis ferruginia (34), and leaves, stems, and roots of Artocarpus integra (22). It has also been found in numerous microorganisms (21), as well as in animals.…”