Photosynthetic characteristics of three varieties of Lilium “Oriental Hybrids” in the central areas of Yunnan Province, China

To understand the ecophysiological adapta-tion of Lilium "Oriental Hybrids", which are grown for their commercial bulbs, the gas exchange, leaf N and chlorophyll content of the three varieties were investigated in the central areas of the Yunnan Province. Among the three varieties, light-saturated photosynthetic rate at ambient CO2 (Amax) of Tiber was the highest, while that of Siberia was the lowest. The difference in the Amax was related to the carboxylation efficiency (CE), leaf mass per unit area and leaf N content per mass, which indicated that their photosynthetic capacity was influenced by the activity and/or the quantity of Rubisco. The three vari-eties had lower photosynthetic saturation points and pho-tosynthetic compensation points, but the photosynthetic rates were not decreased up to 2000 μmol.m-2s-1 of the light intensity. This indicates that the three varieties had broad adaptability to light intensity. There were signifi-cant differences in the photosynthetic optimum temper-ature among the three varieties. Siberia had the highest photosynthetic optimum temperature (25.5℃-34.9℃), and is likely to grow well in warm areas. Sorbonne had the lowest photosynthetic optimum temperature (19.3℃-25.6℃), and its growth is favored in cool areas. Tiber can maintain a high photosynthetic rate within a wide range of temperature. Therefore, Tiber is the most suitable variety for the climate in the central areas of the Yunnan Province, China.     

Distance-based measurement determines the coexistence of B protein hetero- and homodimers in lily tepal and stamen tetrameric complexes

The floral quartet model proposes that plant MADS box proteins function as higher order tetrameric complexes. However, in planta evidence for MADS box tetramers remains scarce. Here, we applied a strategy using in vivo fluorescence resonance energy transfer (FRET) based on the distance change and distance symmetry of stable tetrameric complexes in tobacco (Nicotiana benthamiana) leaf cells to improve the accuracy of the estimation of heterotetrameric complex formation. This measuring system precisely verified the stable state of Arabidopsis petal (AP3/PI/SEP3/AP1) and stamen (AP3/PI/SEP3/AG) complexes and showed that the lily (Lilium longiflorum) PI co-orthologs LMADS8 and LMADS9 likely formed heterotetrameric petal complexes with Arabidopsis AP3/SEP3/AP1, which rescued petal defects of pi mutants. However, L8/L9 did not form heterotetrameric stamen complexes with Arabidopsis AP3/SEP3/AG to rescue the stamen defects of the pi mutants. Importantly, this system was applied successfully to find complicated tepal and stamen heterotetrameric complexes in lily. We found that heterodimers of B function AP3/PI orthologs (L1/L8) likely coexist with the homodimers of PI orthologs (L8/L8, L9/L9) to form five (two most stable and three stable) tepal- and four (one most stable and three stable) stamen-related heterotetrameric complexes with A/E and C/E function proteins in lily. Among these combinations, L1 preferentially interacted with L8 to form the most stable heterotetrameric complexes, and the importance of the L8/L8 and L9/L9 homodimers in tepal/stamen formation in lily likely decreased to a minor part during evolution. The system provides substantial improvements for successfully estimating the existence of unknown tetrameric complexes in plants.     

山丹百合鳞茎提取液中活性物质及其对樱桃番茄的保鲜效果

以山丹百合鳞茎和樱桃番茄'碧姣'果实为材料,分析不同浓度(0～1.0 g/L,以不做任何处理为对照CK)百合鳞茎提取液在低温(5℃)和常温(20℃)贮藏期间对樱桃番茄果实感观品质、营养品质和超氧化物歧化酶(SOD)活性的影响,并采用比色法、比浊法等方法测定提取液中活性成分含量及其抗氧化能力、抑菌活性,探究山丹百合鳞茎浸...