He Jie, Qin Lin, Chong Emma L C, Choong Tsui-Wei, Lee Sing Kong
National Institute of Education, Nanyang Technological University Singapore, Singapore.
Front Plant Sci. 2017 Mar 17;8:361. doi: 10.3389/fpls.2017.00361. eCollection 2017.
is a succulent, facultative crassulacean acid metabolism (CAM) plant. Plant growth and photosynthetic characteristics were studied when plants were grown indoor under light emitting diodes (LED)-lighting with adequate water supply. Plants were cultured aeroponically for a 16-h photoperiod at an equal photosynthetic photon flux density of 350 μmol m s under different red:blue LED ratios: (1) 100:0 (0B); (2) 90:10 (10B); (3) 80:20 (20B); (4) 70:30 (30B); (5) 50:50 (50B); and (6)100:0 (100B). grown under 10B condition had the highest shoot and root biomass and shoot/root ratio while those grown under 0B condition exhibited the lowest values. Compared to plants grown under 0B condition, all other plants had similar but higher total chlorophyll (Chl) and carotenoids (Car) contents and higher Chl / ratios. However, there were no significant differences in Chl/Car ratio among all plants grown under different red- and blue-LEDs. Photosynthetic light use efficiency measured by photochemical quenching, non-photochemical quenching, and electron transport rate, demonstrated that plants grown under high blue-LED utilized more light energy and had more effective heat dissipation mechanism compared to plants grown under 0B or lower blue-LED. Statistically, there were no differences in photosynthetic O evolution rate, light-saturated CO assimilation rate (), and light-saturated stomatal conductance () among plants grown under different combined red- and blue-LEDs but they were significantly higher than those of 0B plants. No statistically differences in total reduced nitrogen content were found among all plants. For the total soluble protein, all plants grown under different combined red- and blue-LEDs had similar values but they were significantly higher than that of plants grown under 0B condition. However, plants grown under higher blue-LEDs had significant higher ribulose-1,5-bisphosphate carboxylase oxygenase (Rubisco) protein than those plants grown under lower blue-LED. High and but very low CAM acidity of all plants during light period, imply that this facultative CAM plant performed C photosynthesis when supplied with adequate water. Results of this study suggest that compared to red- or blue-LED alone, appropriate combination of red- and blue-LED lighting enhanced plant growth and photosynthetic capacities of .
是一种肉质兼性景天酸代谢（CAM）植物。在室内发光二极管（LED）照明且水分供应充足的条件下种植该植物时，对其生长和光合特性进行了研究。植物采用气培法培养，光周期为16小时，在不同红蓝光LED比例下光合光子通量密度均为350 μmol m⁻² s⁻¹：（1）100:0（0B）；（2）90:10（10B）；（3）80:20（20B）；（4）70:30（30B）；（5）50:50（50B）；以及（6）100:0（100B）。在10B条件下生长的植株地上部和根部生物量以及根冠比最高，而在0B条件下生长的植株这些值最低。与在0B条件下生长的植株相比，所有其他植株的总叶绿素（Chl）和类胡萝卜素（Car）含量相似但更高，且Chl / 比值更高。然而，在不同红蓝光LED组合下生长的所有植株之间，Chl/Car比值没有显著差异。通过光化学猝灭、非光化学猝灭和电子传递速率测量的光合光利用效率表明，与在0B或低蓝光LED条件下生长的植株相比，在高蓝光LED条件下生长的植株利用了更多光能且具有更有效的散热机制。统计学上，在不同红蓝光LED组合下生长的植株之间，光合放氧速率、光饱和CO₂同化速率（）和光饱和气孔导度（）没有差异，但它们显著高于0B植株。所有植株的总还原氮含量没有统计学差异。对于总可溶性蛋白，在不同红蓝光LED组合下生长的所有植株的值相似，但显著高于在0B条件下生长的植株。然而，在较高蓝光LED条件下生长的植株的核酮糖-1,5-二磷酸羧化酶加氧酶（Rubisco）蛋白显著高于在较低蓝光LED条件下生长的植株。所有植株在光照期间具有较高的和但极低的CAM酸度，这意味着这种兼性CAM植物在水分供应充足时进行C₃光合作用。本研究结果表明，与单独的红光或蓝光LED相比，适当组合红蓝光LED照明可增强该植物的生长和光合能力。
