Translocation of Sugars in the Concord Grape.

Swanson, C. A.; El-Shishiny, E. D. H.

doi:10.1104/pp.33.1.33

Cited by 120 publications

(51 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…If the exudate comes mainly from the phloem, this dependence is readily explained as a consequence of enhanced photosynthesis and phloem loading of photosynthate in the blade (20 (Table IV), presumably through metabolism of [14CJsu-crose translocated into the sheath. The heavier labeling of glucose than fructose in sheath extracts (Table IV) probably reflects differential utilization (21). second and third leaves, and exposed for 30 min to 14C02 generated from Na214CO3.…”

Section: B Evidence That Exudate Is Principally Of Phloem Originmentioning

confidence: 99%

Amino Acids Translocated from Turgid and Water-stressed Barley Leaves

Tully

Hanson²

1979

Plant Physiol.

View full text Add to dashboard Cite

The phloem exudation technique of King and Zeevaart (Plant Physiol 1974 53: 96-103) was modified for use with barley plants, to investigate the effect of water stress upon amino acid translocation at seedling and grainfilled stages.Seedling leaves and flag leaves from unstressed and moderately waterstressed plants exuded "CO2 assimilates, sugars, and amino acids when their sheaths were cut and immersed in a 5 millimolar solution of Na2EDTA (pH 7.0). By including PEG 6000 (-10 bars) Major amino acids in exudate from unstressed seedling and flag leaves were glutamine, glutamate, serine, alanine, and aspartate; proline was virtually absent. Exudate from water-stressed leaves contained relatively more serine, and also some proline and y-aminobutyric acid.While sucrose is well established as the principal sugar transported in the phloem of cereals (e.g. 3), there are few previous reports on the nitrogenous phloem constituents in these crops ( 18). The N-compounds moving in the phloem of cereals may originate from either or both of the following sources: (a) recent N assimilation (18, 23 and refs. cited therein), and (b) hydrolysis of leaf proteins, which occurs during senescence (1) and episodes of water stress (23). Although it is clear that the relative importance of sources (a) and (b) changes both with developmental stage and with environmental conditions, little is known about the chemical forms of N which these sources make available for phloem transport. Such descriptive information on the N-compounds in the phloem of cereals is pertinent to understanding the striking capacity of these plants to remobilize N from leaves and stems, sometimes directing over 70%'o of total plant N to the grains; it is also needed for quantitative treatments of partitioning of assimi- (23), and were used at 19 days (three-leaf stage), or at 21 to 24 days (four-leaf stage). Such plants were water-stressed by flooding the roots with polyethylene glycol (PEG 6000) solution 1 day prior to use, as described previously (23). Plants for experiments with flag leaves were grown in the greenhouse in a soil mixture (7)

show abstract

Section: B Evidence That Exudate Is Principally Of Phloem Originmentioning

confidence: 99%

Amino Acids Translocated from Turgid and Water-stressed Barley Leaves

Tully

Hanson²

1979

Plant Physiol.

View full text Add to dashboard Cite

show abstract

“…!lOng_<::_uJtivars (Yang & Horl,T98o). According to Swanson & El-Shishiny (1959) and Koblet (1977) translocation of carbohydrates was,m'! !11ly in_the form of sucrose, w_hi!~ the speed oflig11slm~C;ltion ~as ID9:~cf!l:ZlHK9DI~I, .19-69) .…”

mentioning

confidence: 99%

Distribution of 14C-Photosynthetate in the Shoot of Vitis vinifera L. cv Cabernet Sauvignon I. The Effect of Leaf Position and Developmental Stage of the Vine

Hunter¹,

Visser²

2017

SAJEV

View full text Add to dashboard Cite

The distribution of photosynthetates, originating in leaves of different parts of the shoot of Vi tis vinifera L. cv Cabernet Sauvignon at berry set, pea size, veraison and ripeness stages, was investigated. Specific photosynthetic activity of the "CO,-treated leaves gradually decreased during the season. Photosynthetates were hoarded in the leaves at berry set, but were increasingly diverted to the bunches after that. The apical leaves displayed the Itlghes.t.photosynthesis. The leaves opposite and below the bunches accumulated very little photosynthetafes, especially from veraison to ripeness. Redistribution of photosynthetates among the basal, middle and apical leaves was generally very restricted at all stages. Multidirectional distribution from the site of application of 14 CO, occurred at berry set stage, while from pea size to ripeness photosynthetates were mainly translocated basipetally. Highest accumulation in the bunches occurred at veraison, while the basal leaves were primarily used to nourish the bunch.

show abstract

“…In plants in which we consider only one mobile carrier of label such as sucrose in our Acer negundo (6), the ratio of stationary metabolic derivatives (hexoses) to mobile carrier (sucrose) decreases with distance from supply, giving convincing support for the suggestion of sucrose translocation. This is a relatively straightforward interpretation based on few tenuous assumptions.…”

Section: Discussionmentioning

confidence: 82%