Contoh phloem

• Another explanation could be the lack in maize of specific signal sequences for the transport to phloem sap.

• It feeds on the phloem in leaf sheaths, causing wilting and drying of the leaves.

• Analysis of these sequences demonstrated high similarity among the phloem-restricted isolates and confirmed the existence of 2 main groups.

• The term bark is used here to refer collectively to vascular cambium, phloem, cortex and periderm.

• By contrast, the developmental changes in phloem sap composition were consistent between years, indicating a role for phloem sap quality in the aphid population crash.

• This was attributed in part to a lowered concentration of phloem amino acids and in part to difficulties in achieving phloem ingestion.

• Aphids and other pests are obligatory phloem sap feeders, and they represent important prey for beneficial insects such as predators and parasitoids.

• Another open question is whether the transgene product could be transported in the phloem sap.

• To reach the phloem sieve elements the aphid's stylet mouthparts must pierce a series of plant tissues.

• The enlarged cambial cells appeared to crush the phloem and were thus presumed to cause the hopperburn symptom characteristic of the leafhopper damage.

• The sugar-rich phloem is a possible niche for such organisms.

• It is not known whether disproportionately higher levels of alkaloids in other tissues, principally the phloem, contribute to this aphid resistance.

• This result contrasts with plant responses to phloem-feeding insects.

• Since aphids are specialist herbivores targeting the phloem sieve element, it is reasonable to expect that changes in gene expression may be phloem-specific.

• The specialist race found its host plant faster, reached the phloem sooner, and spent more time feeding than the generalist one.