In plants, non-green plastids in heterotrophic tissues are sites for starch and fatty acids biosynthesis,which are essential for plant development and reproduction. Distinct from chloroplasts, the metabolites for thes...In plants, non-green plastids in heterotrophic tissues are sites for starch and fatty acids biosynthesis,which are essential for plant development and reproduction. Distinct from chloroplasts, the metabolites for these processes in non-green plastids have to be imported through specific transporters. Glucose 6-Phosphate/Phosphate Translocator 1 is required for the uptake of cytosolic Glucose 6-Phosphate into non-green plastids. In Arabidopsis, GPT1 has been demonstrated to play essential roles in male, female gametophyte and embryo development. However, the roles of GPTs in other species are yet largely unknown. Here, we reported that rice OsGPT1 is indispensable for normal tapetal degeneration and pollen exine formation during anther and pollen development. OsGPT1 is localized in the plastid and distributed in the anther wall layers and late-stage pollen grains. Different from the gametic defects caused by mutation in At GPT1, disruption of OsGPT1 does not affect male and female gamete transmission as well as embryo development. On the contrary, osgpt1 mutant exhibits delayed tapetum degeneration,decreased Ubisch bodies formation and thinner pollen exine, leading to pollen abortion at the mature stage. Furthermore, the expression of several genes involved in tapetal programmed cell death(PCD)and sporopollenin formation is decreased in osgpt1. Our study suggests that OsGPT1 coordinates the development of anther sporophytic tissues and the male gametophyte by integrating carbohydrate and fatty acid metabolism in the plastid.展开更多
Coordination between the sporophytic tissue and the gametic pollen within anthers is tightly controlled to achieve the optimal pollen fitness. Glucose-6-phosphate/phosphate translocator(GPT) transports glucose-6-phosp...Coordination between the sporophytic tissue and the gametic pollen within anthers is tightly controlled to achieve the optimal pollen fitness. Glucose-6-phosphate/phosphate translocator(GPT) transports glucose-6-phosphate, a key precursor of starch and/or fatty acid biosynthesis, into plastids. Here, we report the functional characterization of Os GPT1 in the rice anther development and pollen fertility. Pollen grains from homozygous osgpt1 mutant plants fail to accumulate starch granules, resulting in pollen sterility. Genetic analyses reveal a sporophytic effect for this mutation. Os GPT1 is highly expressed in the tapetal layer of rice anther. Degeneration of the tapetum, an important process to provide cellular contents to support pollen development, is impeded in osgpt1 plants. In addition, defective intine and exine are observed in the pollen from osgpt1 plants. Expression levels of multiple genes that are important to tapetum degeneration or pollen wall formation are significantly decreased in osgpt1 anthers. Previously, we reported that At GPT1 plays a gametic function in the accumulation of lipid bodies in Arabidopsis pollen. This report highlights a sporophytic role of Os GPT1 in the tapetum degeneration and pollen development. The divergent functions of Os GPT1 and At GPT1 in pollen development might be a result of their independent evolution after monocots and dicots diverged.展开更多
基金supported the National Natural Science Foundation of China (U19A2031)the National Key Research and Development Program of China (2016YFD0100903)。
文摘In plants, non-green plastids in heterotrophic tissues are sites for starch and fatty acids biosynthesis,which are essential for plant development and reproduction. Distinct from chloroplasts, the metabolites for these processes in non-green plastids have to be imported through specific transporters. Glucose 6-Phosphate/Phosphate Translocator 1 is required for the uptake of cytosolic Glucose 6-Phosphate into non-green plastids. In Arabidopsis, GPT1 has been demonstrated to play essential roles in male, female gametophyte and embryo development. However, the roles of GPTs in other species are yet largely unknown. Here, we reported that rice OsGPT1 is indispensable for normal tapetal degeneration and pollen exine formation during anther and pollen development. OsGPT1 is localized in the plastid and distributed in the anther wall layers and late-stage pollen grains. Different from the gametic defects caused by mutation in At GPT1, disruption of OsGPT1 does not affect male and female gamete transmission as well as embryo development. On the contrary, osgpt1 mutant exhibits delayed tapetum degeneration,decreased Ubisch bodies formation and thinner pollen exine, leading to pollen abortion at the mature stage. Furthermore, the expression of several genes involved in tapetal programmed cell death(PCD)and sporopollenin formation is decreased in osgpt1. Our study suggests that OsGPT1 coordinates the development of anther sporophytic tissues and the male gametophyte by integrating carbohydrate and fatty acid metabolism in the plastid.
基金supported by the grants from National Natural Science Foundation of China (31922005)Zhejiang Provincial Natural Science Foundation of China (LR18C020001)+2 种基金Zhejiang University K.P.Chao’s High Technology Development Foundation (2018RC016)the Young Elite Scientist Sponsorship Program by CAST (2018QNRC001)111 Project (B14027) to J.X。
文摘Coordination between the sporophytic tissue and the gametic pollen within anthers is tightly controlled to achieve the optimal pollen fitness. Glucose-6-phosphate/phosphate translocator(GPT) transports glucose-6-phosphate, a key precursor of starch and/or fatty acid biosynthesis, into plastids. Here, we report the functional characterization of Os GPT1 in the rice anther development and pollen fertility. Pollen grains from homozygous osgpt1 mutant plants fail to accumulate starch granules, resulting in pollen sterility. Genetic analyses reveal a sporophytic effect for this mutation. Os GPT1 is highly expressed in the tapetal layer of rice anther. Degeneration of the tapetum, an important process to provide cellular contents to support pollen development, is impeded in osgpt1 plants. In addition, defective intine and exine are observed in the pollen from osgpt1 plants. Expression levels of multiple genes that are important to tapetum degeneration or pollen wall formation are significantly decreased in osgpt1 anthers. Previously, we reported that At GPT1 plays a gametic function in the accumulation of lipid bodies in Arabidopsis pollen. This report highlights a sporophytic role of Os GPT1 in the tapetum degeneration and pollen development. The divergent functions of Os GPT1 and At GPT1 in pollen development might be a result of their independent evolution after monocots and dicots diverged.