摘要
9月和 1 2月测定了生长于 3种不同光强 ( 1 0 0 %、36%和 1 6%的自然光 )下生长的乔木荷树、黧蒴和灌木九节、罗伞盆栽幼苗叶片的 Rubisco羧化速率 ( RCR) ,碳酸酐酶 ( CA)活性和细胞间 CO2 浓度 ( Ci)。当生长光强降低时 ,4种供试植物的 RCR和 CA活性明显降低。 9月时生长在 1 6%自然光下荷树的 RCR和 CA比 1 0 0 %自然光者分别降低 5 5 %和 5 0 % ,藜蒴则降低 2 0 %和 35 % ,耐阴的灌木树种的降幅较小 ,仅为 33%～ 38% ( RCR)和 2 2 %～ 30 %( CA)。 1 2月的 RCR和 CA的水平较 9月时低 ,翌年 1月时自然林不同光强下生长的同类植物的 RCA和 CA随光强变化也有类似的趋势。RCR和 CA活性呈正相关性 ,且两者与 Ci呈弱负相关。推测高光强可能有利于激活 Rubisco,促进 CA催化的 CO2 → Dl C(可溶性碳 )→CO2 活性和 Dl
Carboxylation rate of Rubisco (RCR), activity of carbonic anhydrase (CA) and intercellular CO 2 concentration (Ci) were analyzed in September and December, 1998, in leaves of forest plants Schima superba, Castanopsis fissa, Psychotria rubra and Ardsia quinquegona seedlings grown at three different light intensities, which were 100%, 36% and 16% of natural sun light. RCR and CA activity of all tested plants were decreased obviously by declining growth light intensity, In comparison with plant at 100% sunlight, in September, the RCR and CA activity in leaves of Schima superba grown at 16% sunlight declined by 55% and 50%, respectively, while that in leaves of Castanopsis fissa declined by 20% and 35%. The decreasing ranges of RCR and CA activity in shade adapted shrub species. Psychotria rubra and Ardisia quinquegona were less than that of tree species, which decreased by 33% ~ 38% in RCR and by 22% ~ 30% in CA activity. In the same case, the levels of RCR and CA activity measured in December were lower than that in September. Similar changing trend of RCR and CA activity was also found in plants grown in different sites of natural forest with different light conditions sampling in January, next year. There was a positive relationship between RCR and CA ac tivity , and a weak negative relationship between Ci and RCR or CA activity. It is proposed that higher irradiance might promote the activation of Rubisco and induce the increase in CA activity and transport rate of DIC (dissoluble inorganic carbon).
出处
《武汉植物学研究》
CSCD
2001年第4期304-310,共7页
Journal of Wuhan Botanical Research
基金
中国科学院"九五"重点基金项目 ( KZ 95 2 -Jl -1 0 5 )资助
关键词
热带森林植物
生长
光梯度
Rubisco羧化速率
碳酸酐酶活性
细胞间CO2浓度
光强
Subtropical forest plants
Gradient of growth light
Carboxylation rate of Rubisco
Activity of carbonic anhydrase
Intercellular CO 2 concentration
