p pa pb pc pd pe pf pg ph pi pk pl pm pn po pp pr ps pt pu pv pw px py

Перевод: phloem

[существительное]
флоэма

Тезаурус:

1. Bark loss is generally repaired by the formation of new bark, the inevitable result of secondary thickening in dicotyledons as the phloem dies.
2. We show that translocation in the phloem of tomato seedlings can be completely inhibited without effect on the systemic accumulation of pin transcripts and pin activity, and without hindrance to propagated electrical signals.
3. Our results show that the causal agent exits the wounded cotyledon when phloem translocation is blocked, so the systemic effect must either arise from a chemical signal travelling through a route that does not involve the transport of photosynthate, or a physical signal.
4. Our data show that the systemic responses of wound-induced pin activity and electrical signals occur when phloem translocation is inhibited.
5. Thus, whether the wound stimulus arises from mechanical wounding to the cotyledon, or heat injury to leaf 1, a systemic accumulation of pin activity can be correlated with a systemic electrical signal and neither response is affected by the inhibition of phloem translocation.
6. As chilling of the petiole of leaf 1 inhibited phloem translocation for about 20min, we assayed the effects of chilling the petiole on heat stimulus-induced systemic accumulation of pin activity in leaf 2 and on the systemic electrical signal.
7. Damage due to phloem feeders can also be substantial; leaf feeders can be miners or raspers; there can be root feeders e.g. some insect larvae, nematodes, stem-miners and gall-formers where the allocation patterns of plants are over-ridden.
8. In these experiments chilling is necessary, given that the maximum reported speeds of phloem transport (35-;250mmmin -1 ) are such that a chemical signal might exit the wounded cotyledon in a time comparable to that for an electrical signal.
9. But the speed of transmission is high for the transport of a chemical signal in the phloem.
10. Given the spontaneous recovery of the petiole tissue from chilling, it was necessary to excise the wounded cotyledon within the period in which phloem transport is inhibited in order to prevent any delayed movement of a chemical signal from the wound-site through the phloem.
11. Chilling a petiole is, however, a recognized means of inhibiting phloem transport.