Question

What is the function of p proteins in sieve elements?

Answer 1

Phloem is the vascular tissue responsible for the transport of sugars from source tissues (ex. photosynthetic leaf cells) to sink tissues (ex. non-photosynthetic root cells or developing flowers). Other molecules such as proteins and mRNAs are also transported throughout the plant via phloem

Answer 2

They are believed to play in “damage control” when phloem is damaged. Upon the disruption of a sieve element, the P-proteins quickly aggregate at the sieve plate to form a “clot” which prevents the leakage of phloem exudates through the wound.

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