Regulation Of Photosynthetic Carbon Metabolism In Rice Seedlings By Red And Blue Light

Rice(Oryza sativa L.)is one of most important crops in the world including China.Industrial plantation is an important mode of production in current rice seedlings cultivation.The quality of seedlings directly affects the quality of mechanical transplanting production,which then affects subsequent rice production.Light is one of the most important factors,affecting the growth and development of plants.Spectral energy distribution significantly affects plant growth and development,and can directly or indirectly regulate plant life activities such as light morphogenesis,growth and development and physiological metabolism.Carbon metabolism is one of the basic physiological processes of plants,and its metabolites are the material basis of plant growth.Photosynthesis and the activity of enzymes involved in carbon metabolism significantly regulate the process of carbon metabolism.Industrial plantation require a suitable light environment for plant growth.Therefore,the exploration of red light and blue light on growth and photosynthetic carbon metabolism of plant can provide important data for plant production in controlled environment.To this end,we selected ’Ningjing 7’ as the experimental material,under artificial light conditions,and investigated the effect of red and blue light on rice seedling growth,photosynthetic characteristics and carbon metabolism of rice seedling at different stages.The results of this two researches are as follows:(1)The effects of different light quality on rice seedling growth,photosynthetic characteristics and carbon metabolism showed that light quality significantly affected the morphology of rice seedlings.Compared with white light,the plant height,root length and leaf thickness of red-treated rice seedlings increased significantly,and red-blue light significantly reduced stem diameter.Light quality also affects the material accumulation of different organs of rice seedlings.Leaf and total biomass were not affected by spectral changes,but stem dry weights of red-blue and red light treated rice seedlings were significantly reduced compared to white light treatment,while root dry weight of red,blue and red-blue light treatments increased,and the root dry weight of red-treated rice seedlings increased significantly.Light quality significantly affected the accumulation of photosynthetic pigments in rice seedlings,causes changes in photosynthetic characteristics of rice seedlings.Compared with white light,the photosynthetic pigment content of red and blue-treated rice seedlings increased,and the photosynthetic pigment content of red-blue combined light-treated rice seedlings decreased.Under red light,the transpiration rate of rice seedlings decreased significantly,and the water use efficiency increased significantly.Under the combination of blue light and red-blue light,the rice seedlings were just the opposite.The stomatal conductance and intercellular CO2 concentration of rice seedlings increased significantly under different light quality treatments,and the transient carboxylation efficiency decreased significantly.Light quality also had a significant effect on the accumulation of carbon metabolites and key enzyme activities in rice seedlings.Red light treatment increased the accumulation of carbon metabolites in leaves of rice seedlings compared with white light treatment,and increased the activity of sucrose phosphate synthase in sucrose synthase,stem and leaf in leaves;blue light treatment resulted in accumulation of carbon metabolites in rice seedlings.The inhibition of sucrose synthase and sucrose phosphate synthase in stems and leaves was higher than that in white light.The accumulation of sugar in various parts of rice seedlings under red-blue combined light increased significantly,and the activity of sucrose synthase in stems and leaves increased.The results showed that red light and blue light significantly affected the morphogenesis and photosynthetic carbon metabolism of rice seedlings.The light quality not only regulated the accumulation and transport of carbon metabolites in rice seedlings,but also significantly regulated the key enzyme activities during product synthesis and degradation.Red light is conducive to the formation of rice seedlings,and the activity of key enzymes in carbon metabolism of rice seedlings is enhanced by blue light.The red and blue combination is beneficial to the accumulation of carbon metabolites in various parts of rice seedlings.(2)In the actual production of rice breeding,natural light cultivation is a common pattern of rice breeding.Natural light radiated to the ground or plants will change its spectral composition due to changes in meteorological conditions,dust and other conditions,affecting plant production.Therefore,studying the effects of spectral changes on rice seedling growth in different periods establishes basic data to cope with this change and aims to guide rice.Breeding production.Therefore,on the basis of clarifying the regulation of red light and blue light on rice seedling morphogenesis and photosynthetic carbon metabolism,the effects of red light and blue light on rice seedling growth and photosynthetic carbon metabolism in four-leaf stage were studied.The results show that the light quality significantly affects the morphology of the four-leaf stage rice seedlings.Compared with white light,the plant height and stem diameter of red-treated rice seedlings increased significantly,leaf thickness decreased significantly,red and blue light significantly increased stem diameter,and blue light significantly reduced stem thickness and leaf thickness.Light quality changes also affect the material accumulation of different organs in the four-leaf stage rice seedlings.Different light quality treatments significantly reduced the total biomass of rice seedlings.The dry weight of blue light on roots,stems and leaves was significantly inhibited by white light treatment,and red and blue light significantly inhibited stem dry weight.Light quality significantly affected the accumulation of photosynthetic pigments in rice seedlings.Causes changes in photosynthetic characteristics of rice seedlings.Compared with white light,the photosynthetic pigment content of blue-treated rice seedlings decreased significantly,and increased significantly under red and blue light.Different grading treatments caused a significant increase in transpiration rate,a significant decrease in water use efficiency,and a net photosynthetic rate of rice under red light.The transient carboxylation efficiency increased significantly,and the stomatal conductance and intercellular CO2 concentration decreased significantly.Under blue light,the net photosynthetic rate,stomatal conductance and intercellular CO2 concentration of rice seedlings increased significantly,and the transient carboxylation efficiency decreased significantly.Light quality also had a significant effect on the accumulation of carbon metabolites and key enzyme activities in rice seedlings.Different light treatments resulted in significantly lower sucrose synthase activity in stems and leaves of rice seedlings than in white light treatment.Red light treatment increased the accumulation of sucrose,starch and soluble total sugar in rice seedling leaves,and blue light treatment resulted in root and stem carbon metabolites.Accumulation was inhibited to a certain extent,which was conducive to the accumulation of leaf products.Red and blue light significantly promoted the accumulation of sucrose,starch and soluble total sugar in sucrose and leaves,and inhibited the activity of sucrose phosphate synthase in stems.The results showed that red light and blue light significantly affected the morphogenesis and photosynthetic carbon metabolism of rice seedlings in four-leaf stage,red light was beneficial to the morphogenesis of four-leaf stage rice seedlings,and blue light had different degrees of morphogenesis and photosynthetic in four-leaf stage rice seedlings.The inhibition effect,red blue light is conducive to the accumulation of carbon metabolites in rice seedling leaves is a good light quality choice for breeding.The effects of spectral treatment on the growth of rice blast in different periods were compared and found.The effect of red light on the irradiation of four-leaf seedlings was similar to that of red light at the beginning of breeding,while the blue light treatment was significantly different,indicating that rice blasts were different.The growth phase is insensitive to red light response,while rice blasts at diferent growth stages are sensitive to changes in the blue light spectrum.The quality of rice seedlings treated with red and blue composite light treatment was significantly lower than that of red light treatment seedlings,but the red-blue light treatment in the four-leaf stage significantly promoted the morphogenesis and carbohydrate accumulation of rice seedlings.The growth period of rice seedlings was also sensitive to red and blue.changes in the spectrum.In summary,it was found that red light and blue light significantly affected the growth and photosynthetic characteristics of rice seedlings,and involved in the regulation of the synthesis and degradation of carbon metabolites in rice seedlings,affecting the distribution of photosynthetic products and the accumulation of substances in different organs.At the same time,the treatment period of light quality affects the growth,photosynthetic characteristics and carbon metabolism of rice seedlings.The response of rice seedlings in different growth stages to the same spectrum has different effects due to different spectra.The growth period of rice seedlings is not sensitive to red light,but sensitive to changes in blue and red and blue composite light.