Improved Tolerance of Teak (Tectona grandis L.f.) Seedlings to Low-Temperature Stress by the Combined Effect of Arbuscular Mycorrhiza and Paclobutrazol

• Published in: Journal of plant growth regulation 2012-09, Vol.31 (3), p.427-435
• Main Authors: Zhou, Zaizhi, Ma, Huaming, Liang, Kunnan, Huang, Guihua, Pinyopusarerk, Khongsak
• Format: Article
• Language: English
• Subjects: Agriculture; Antioxidants; arbuscular mycorrhizas; Biomass; biomass production; Biomedical and Life Sciences; Chilling; Chlorophyll; Climate; clones; cold tolerance; Colonization; Culture techniques; Enzymes; foliar spraying; Fungi; Glomus versiforme; Greenhouses; Inoculation; Leaves; Life Sciences; Lipid peroxidation; Low temperature; Malondialdehyde; mycorrhizal fungi; paclobutrazol; Peroxidase; Peroxidation; Photosynthetic pigments; pigments; Plant Anatomy/Development; Plant Physiology; Plant Sciences; protein content; provenance; Roots; Seedlings; Shoots; Spraying; Stress; Superoxide dismutase; Symbiosis; Tectona grandis; temperature; Temperature effects; Tissue culture; vesicular arbuscular mycorrhizae
• ISSN: 0721-7595; 1435-8107
• DOI: 10.1007/s00344-011-9252-6

Low-temperature damage is a common problem for tropical and subtropical plants during their early-growth stage. In this study, an experiment with a L18 (21 × 37) mixed orthogonal array in a greenhouse was conducted to determine whether arbuscular mycorrhizal fungi (AMF) inoculation and paclobutrazol (PBZ) application through foliar spray would enhance the chilling tolerance of teak seedlings. One-month-old seedlings of clones 8301, 7544, and 7552 from a Myanmar provenance propagated by tissue culture techniques were inoculated with Glomus versiforme and cultivated for 6 months. The foliar surface of both mycorrhizal and nonmycorrhizal treated plants was sprayed with PBZ at concentrations of 0, 50, and 100 mg l−1 once a week for 3 weeks prior to exposure to low temperatures of 6, 3, and 0°C for 12 h in an artificial climate chamber, followed by 12 h of recovery at 20°C room temperature. AMF colonization significantly promoted height and RCD growth and dry biomass accumulation of shoot and root. Under low-temperature stress, AM symbiosis increased leaf chlorophyll content by 22.8%, soluble protein content by 19.6%, superoxide dismutase (SOD) activity by 10.6%, and peroxidase (POX) activity by 9.5%, whereas malondialdehyde content was decreased by 14.1%. Both AMF colonization and the foliar spray PBZ at 50 and 100 mg l−1 were capable of alleviating the damage caused by low-temperature stress on teak seedlings by increasing the photosynthetic pigments, accumulation of osmotic adjustment compounds, and antioxidant enzyme (SOD and POX) activity, and by decreasing membrane lipid peroxidation. AMF colonization and foliar spraying of PBZ at 50 mg l−1 produced a positive interaction and appears to be a good way to enhance chilling tolerance of teak seedlings experiencing stress at 6, 3 and 0°C for 12 h.