This is a preview. Log in through your library . Abstract Light microscopic studies of the petioles of Lagenaria siceraria reveal that the external phloem of each bicollateral vascular bundle develops ...

Sieve tubes play important roles in the transfer of nutrients as well as signals. Hundreds of proteins were found in pure phloem sap collected from rice (Oryza sativa L. cv. Kantou) plants through the ...