Shandong has more than 70% of natural coasts are under erosion.Coastal erosion started from the 1970's and became a very serious problem at 1990 's.The dramatic decrease of sediment supplies from rivers caused...Shandong has more than 70% of natural coasts are under erosion.Coastal erosion started from the 1970's and became a very serious problem at 1990 's.The dramatic decrease of sediment supplies from rivers caused rapid erosion at the delta and estuary areas,especially in the abandoned Yellow River Delta.Most sandy coasts along the Peninsula were eroded due to lack of sand supply and interruption of alongshore sediment drift,sand dredging from the beach or the offshore area caused serious erosion during short time. Sea-level rise causes slow but constant shoreline retreats and became a more serious threat.Different types of hard solutions for coastal protection against erosion were used in Shandong.Seawalls are most widely used,especially at the Yellow River Delta and city center waterfront.Groynes,jetties and breakwater are used on the north and east sandy coast of the Peninsula.Hard approaches are effective to protect the coast erosion but not change the erosion causes and led secondary impact on the coast.Soft engineering solution or the combined solutions are taken into acts.Beach nourishment is mostly considered as the better soft solution,especially to those tourists attracting sandy beaches along the Shandong coast.Long term monitoring and continuous lessons learning from the coastal erosion management will be adaptive for better coast solution in the future.展开更多
Pollen fertility is a crucial factor for successful pollination and essential for seed formation. Recent studies have suggested that a diverse range of internal and external factors, signaling components and their rel...Pollen fertility is a crucial factor for successful pollination and essential for seed formation. Recent studies have suggested that a diverse range of internal and external factors, signaling components and their related pathways are likely involved in pollen fertility. Here, we report a single C2-domain containing protein, OsPBP1, initially identified through cDNA microarray analysis. OsPBP1 is a single copy gene and preferentially expressed in pistil and pollen but downregulated by pollination. OsPBP1 had a calcium concentration-dependent phospholipid-binding activity and was localized mainly in cytoplasm and nucleus, but translocated onto the plasma membrane in response to an intracellular Ca^2＋ increase. Pollen grains of antisense OsPBP1 transgenic lines were largely nonviable, germinated poorly in vitro and of low fertility. OsPBP1 protein was localized in a region peripheral to pollen wall and vesicles of elongating pollen tube, and its repressed expression reduced substantially this association and led to alteration of microfilament polymerization during pollen germination. Taken together, these results indicate that OsPBP1 is a novel functional C2-domain phospholipids-binding protein that is required for pollen fertility likely by regulating Ca^2＋ and phospholipid signaling pathways.展开更多
文摘Shandong has more than 70% of natural coasts are under erosion.Coastal erosion started from the 1970's and became a very serious problem at 1990 's.The dramatic decrease of sediment supplies from rivers caused rapid erosion at the delta and estuary areas,especially in the abandoned Yellow River Delta.Most sandy coasts along the Peninsula were eroded due to lack of sand supply and interruption of alongshore sediment drift,sand dredging from the beach or the offshore area caused serious erosion during short time. Sea-level rise causes slow but constant shoreline retreats and became a more serious threat.Different types of hard solutions for coastal protection against erosion were used in Shandong.Seawalls are most widely used,especially at the Yellow River Delta and city center waterfront.Groynes,jetties and breakwater are used on the north and east sandy coast of the Peninsula.Hard approaches are effective to protect the coast erosion but not change the erosion causes and led secondary impact on the coast.Soft engineering solution or the combined solutions are taken into acts.Beach nourishment is mostly considered as the better soft solution,especially to those tourists attracting sandy beaches along the Shandong coast.Long term monitoring and continuous lessons learning from the coastal erosion management will be adaptive for better coast solution in the future.
文摘Pollen fertility is a crucial factor for successful pollination and essential for seed formation. Recent studies have suggested that a diverse range of internal and external factors, signaling components and their related pathways are likely involved in pollen fertility. Here, we report a single C2-domain containing protein, OsPBP1, initially identified through cDNA microarray analysis. OsPBP1 is a single copy gene and preferentially expressed in pistil and pollen but downregulated by pollination. OsPBP1 had a calcium concentration-dependent phospholipid-binding activity and was localized mainly in cytoplasm and nucleus, but translocated onto the plasma membrane in response to an intracellular Ca^2＋ increase. Pollen grains of antisense OsPBP1 transgenic lines were largely nonviable, germinated poorly in vitro and of low fertility. OsPBP1 protein was localized in a region peripheral to pollen wall and vesicles of elongating pollen tube, and its repressed expression reduced substantially this association and led to alteration of microfilament polymerization during pollen germination. Taken together, these results indicate that OsPBP1 is a novel functional C2-domain phospholipids-binding protein that is required for pollen fertility likely by regulating Ca^2＋ and phospholipid signaling pathways.
