@entity3363 , mainly @entity969 , that are synthesized in source organs are transported to sink organs to support growth and development. Phloem loading of @entity969 is a crucial step that drives long-distance transport by elevating hydrostatic pressure in the phloem. Three phloem loading strategies have been identified, two active mechanisms, apoplastic loading via @entity969 transporters and symplastic polymer trapping, and one passive mechanism. The first two active loading mechanisms require metabolic energy, @entity1735 is loaded into the phloem against a concentration gradient. The passive process, diffusion, involves equilibration of @entity969 and other metabolites between cells through plasmodesmata. Many higher plant species including @entity958 utilize the active loading mechanisms to increase @entity1735 in the phloem to higher concentrations than that in mesophyll cells. In contrast, recent data revealed that a large number of plants, especially woody species, load @entity969 passively by maintaining a high concentration in mesophyll cells. However, it still remains to be determined how the worldwide important cereal crop, @entity579 , loads @entity969 into the phloem in source organs. Based on the literature and our results, we propose a potential strategy of phloem loading in @entity579 . Elucidation of the phloem loading mechanism should improve our understanding of @entity579 development and facilitate its manipulation towards the increase of crop productivity.

The mechanism of phloem loading in XXXX ( @entity579 ).

@entity958 :: ('3702', 'Species') :: ['Arabidopsis'] @entity1735 :: ('CHEBI:16646', 'Chemical') :: ['carbohydrate'] @entity969 :: ('MESH:D013395', 'Chemical') :: ['sucrose'] @entity579 :: ('4530', 'Species') :: ['rice'] @entity3363 :: ('MESH:D002241', 'Chemical') :: ['Carbohydrates']
@entity579 :: (4530,Species) :: ['rice']
