Background Light is a critical factor in plant growth and development,particularly in controlled environments.Light-emitting diodes(LEDs)have become a reliable alternative to conventional high pressure sodium(HSP)lamp...Background Light is a critical factor in plant growth and development,particularly in controlled environments.Light-emitting diodes(LEDs)have become a reliable alternative to conventional high pressure sodium(HSP)lamps because they are more efficient and versatile in light sources.In contrast to well-known specialized LED light spectra for vegetables,the appropriate LED lights for crops such as cotton remain unknown.Results In this growth chamber study,we selected and compared four LED lights with varying percentages(26.44%–68.68%)of red light(R,600–700 nm),combined with other lights,for their effects on growth,leaf anatomy,and photosynthesis of cotton seedlings,using HSP lamp as a control.The total photosynthetic photon flux density(PPFD)was(215±2)μmol·m-2·s-1 for all LEDs and HSP lamp.The results showed significant differences in all tested parameters among lights,and the percentage of far red(FR,701–780 nm)within the range of 3.03%–11.86%was positively correlated with plant growth(characterized by leaf number and area,plant height,stem diameter,and total biomass),palisade layer thickness,photosynthesis rate(Pn),and stomatal conductance(Gs).The ratio of R/FR(4.445–11.497)negatively influenced the growth of cotton seedlings,and blue light(B)suppressed stem elongation but increased palisade cell length,chlorophyll content,and Pn.Conclusion The LED 2 was superior to other LED lights and HSP lamp.It had the highest ratio of FR within the total PPFD(11.86%)and the lowest ratio of R/FR(4.445).LED 2 may therefore be used to replace HPS lamp under controlled environments for the study of cotton at the seedling stage.展开更多
For most organisms,molecular oxygen is indispensable for normal physiological metabolism;in humans,prolonged hypoxia in tissues can induce many diseases,exemplified by cardiovascular disease,chronic wounds,and tissue ...For most organisms,molecular oxygen is indispensable for normal physiological metabolism;in humans,prolonged hypoxia in tissues can induce many diseases,exemplified by cardiovascular disease,chronic wounds,and tissue necrosis.Therefore,the oxygen in our environment is vital for life.As a main source of oxygen in the natural world that transforms light energy into chemical energy and oxygen,photosynthesis has been widely studied in scientific research and used in production of food,fuel,and medicine.In recent years,photosynthesis has become more closely involved in biomedicine and has been widely used in photodynamic therapy,tissue regeneration,transplantation,and in treatment of specific diseases.This review summarizes innovative applications of photosynthesis in biomedical research and highlights the theory and implications of clinical treatment for specific diseases.展开更多
Through scanning electron microscope and optical microscope, a compara- tive study on morphological features and anatomical characters of the leaves of some pear cultivars （strains） was carried out. The results show...Through scanning electron microscope and optical microscope, a compara- tive study on morphological features and anatomical characters of the leaves of some pear cultivars （strains） was carried out. The results showed that the size and shapes of leaf epidermal cells were different, stomatal apparatuses were distributed in the hypodermis, the shapes of stornas were mainly oval, and these of ＇Jinxiang- shui＇ were long oval; the stomatal type was irregular, the cultivar with the maximum density of leaf stomas was ＇Jinxiangshui＇, and the minimum was ＇Aishanli＇. The thickness of palisade tissues and spongy tissues of different pear cultivars （strains） was different, the maximum thickness of palisade tissues of ＇Aishanli＇ was 105.5 iJm, and the maximum thickness of spongy tissues of ＇Jinxiangshui＇ was 98.4 IJm. The ratios of palisade tissues to spongy tissues from high to low were ＇Qiuyueli＇, ＇Zaoxiangshui＇, ＇Aishanli＇, ＇Hongjinqiu＇ and ＇8404＇. The differences on these mi- cromorphological characters among different pear cultivars （strains） had important significance to the identification of the cultivars and the early choice of breeding.展开更多
基金funded by the China Agriculture Research System(CARS-15-16).
文摘Background Light is a critical factor in plant growth and development,particularly in controlled environments.Light-emitting diodes(LEDs)have become a reliable alternative to conventional high pressure sodium(HSP)lamps because they are more efficient and versatile in light sources.In contrast to well-known specialized LED light spectra for vegetables,the appropriate LED lights for crops such as cotton remain unknown.Results In this growth chamber study,we selected and compared four LED lights with varying percentages(26.44%–68.68%)of red light(R,600–700 nm),combined with other lights,for their effects on growth,leaf anatomy,and photosynthesis of cotton seedlings,using HSP lamp as a control.The total photosynthetic photon flux density(PPFD)was(215±2)μmol·m-2·s-1 for all LEDs and HSP lamp.The results showed significant differences in all tested parameters among lights,and the percentage of far red(FR,701–780 nm)within the range of 3.03%–11.86%was positively correlated with plant growth(characterized by leaf number and area,plant height,stem diameter,and total biomass),palisade layer thickness,photosynthesis rate(Pn),and stomatal conductance(Gs).The ratio of R/FR(4.445–11.497)negatively influenced the growth of cotton seedlings,and blue light(B)suppressed stem elongation but increased palisade cell length,chlorophyll content,and Pn.Conclusion The LED 2 was superior to other LED lights and HSP lamp.It had the highest ratio of FR within the total PPFD(11.86%)and the lowest ratio of R/FR(4.445).LED 2 may therefore be used to replace HPS lamp under controlled environments for the study of cotton at the seedling stage.
基金This work was supported by Grants from the National Natural Science Foundation of China(Nos.81671918 and 81372072)the Zhejiang Provincial Medical and Healthy Science Foundation of China(Nos.2021452516,2019ZD028,and 2018KY874)the National Key Research Program of China(No.2016YFC1101004).
文摘For most organisms,molecular oxygen is indispensable for normal physiological metabolism;in humans,prolonged hypoxia in tissues can induce many diseases,exemplified by cardiovascular disease,chronic wounds,and tissue necrosis.Therefore,the oxygen in our environment is vital for life.As a main source of oxygen in the natural world that transforms light energy into chemical energy and oxygen,photosynthesis has been widely studied in scientific research and used in production of food,fuel,and medicine.In recent years,photosynthesis has become more closely involved in biomedicine and has been widely used in photodynamic therapy,tissue regeneration,transplantation,and in treatment of specific diseases.This review summarizes innovative applications of photosynthesis in biomedical research and highlights the theory and implications of clinical treatment for specific diseases.
文摘Through scanning electron microscope and optical microscope, a compara- tive study on morphological features and anatomical characters of the leaves of some pear cultivars （strains） was carried out. The results showed that the size and shapes of leaf epidermal cells were different, stomatal apparatuses were distributed in the hypodermis, the shapes of stornas were mainly oval, and these of ＇Jinxiang- shui＇ were long oval; the stomatal type was irregular, the cultivar with the maximum density of leaf stomas was ＇Jinxiangshui＇, and the minimum was ＇Aishanli＇. The thickness of palisade tissues and spongy tissues of different pear cultivars （strains） was different, the maximum thickness of palisade tissues of ＇Aishanli＇ was 105.5 iJm, and the maximum thickness of spongy tissues of ＇Jinxiangshui＇ was 98.4 IJm. The ratios of palisade tissues to spongy tissues from high to low were ＇Qiuyueli＇, ＇Zaoxiangshui＇, ＇Aishanli＇, ＇Hongjinqiu＇ and ＇8404＇. The differences on these mi- cromorphological characters among different pear cultivars （strains） had important significance to the identification of the cultivars and the early choice of breeding.
