High Light Intensity Increases the CAM Expression in “MD-2” Micro-Propagated Pineapple Plants at the End of the Acclimatization Stage

• 作者: Carlos E. Aragón Dariel López Florencio E. Podestá Gustavo Y. Lorente Justo L. González-Olmedo René C. Rodríguez-Escriba Romelio Rodríguez Yaima Pino Yolanda Garza
• 来源期刊: 美国植物学期刊(英文)
• 学科: 医学
• 关键词: Crassulacean Acid Metabolism HARDENING STAGE Ex VITRO Vitroplants Gaseous Exchange
• 年，卷（期）: 2015,（19）
• 页码范围: 3109-3118
• 页数: 10页
• 分类号: R73

摘要

This work describes the evaluation of morpho-physiological and biochemical changes in “MD-2” micro-propagated pineapple plants (Ananas comosus (L.) Merr.) grown after 30 days under low light intensity (LL, greenhouse light conditions at 250 μmol·m-2·s-1) or high light intensity (HL, field light conditions at 800 μmol·m-2·s-1). Gas exchange, leaf pH, protein content and superoxide dismutase activity (SOD) (EC 1.15.1.1) were measured every 3 h during one day. Chlorophylls content and succulence index (SI) were determined at 9 h. Results showed significant differences in CO2 exchange rates, with a maximum occurring at 6 h (3.00 and 8.25 μmol CO2 m-2·s-1 for leaves under LL and HL conditions respectively). Plants under HL conditions had higher CO2 uptake and lower pH values between 0 h and 6 h respective to LL plants. The maximum pH value was attained 3 h before in HL plants. Leaf SI was increased and chlorophyll content decreased by HL conditions. SOD activity was higher in plants under HL conditions, near doubling those of LL plants at 18 h (2.8 versus 1.5 U·mg-1 Protein respectively). Both groups showed a typical CAM phenotype, but it was stronger in HL conditions, which may confer these plants with a better acclimation to transfer to the field.