Spectral light distribution affects photosynthesis, leaf reflective indices, antioxidant activity and growth of Vanillaplanifolia

• Published in: Plant physiology and biochemistry Vol. 182; pp. 145 - 153
• Main Authors: Sanchez, Federico, Bassil, Elias, Crane, Jonathan H., Shahid, Muhammad A., Vincent, Christopher I., Schaffer, Bruce
• Format: Journal Article
• Language: English
• Published: France Elsevier Masson SAS 01.07.2022
• Subjects: Antioxidants - metabolism; Chlorophyll - metabolism; Hydrogen Peroxide - metabolism; Leaf gas exchange; Leaf spectral reflective indices; Light; Nocturnal net CO2 assimilation; Photoselective shade netting; Photosynthesis - physiology; Plant Leaves - metabolism; Plants - metabolism; Reactive oxygen species; Vanilla planifolia; Reactive oxygen species; Vanilla planifolia; Leaf spectral reflective indices; Photoselective shade netting; Nocturnal net CO2 assimilation; Leaf gas exchange; Nocturnal net CO assimilation
• ISSN: 0981-9428; 1873-2690
• DOI: 10.1016/j.plaphy.2022.04.020

Vanilla planifolia is an obligate sciophyte (shade plant) with crassulacean acid metabolism (CAM) photosynthesis. Plants were grown for 12 months under black, blue, green, or red photoselective shade netting (PSN) to alter the spectral light distribution impacting the plants. Light wavelengths were measured in each treatment and plants were assessed for photosynthetic characteristics, leaf chlorophyll index (LCI), maximum quantum yield of photosystem II, leaf reflectance indices, leaf area, growth, antioxidant enzymes, lipid peroxidation, reactive oxygen species (ROS), and osmolyte content. Plants grown under red PSN had a higher quantity of red and far-red light and had greater nocturnal net CO2 assimilation (NocA), leaf area and leaf dry weight than plants in the other treatments. Plants grown under blue PSN had a higher quantity of blue light, resulting in a higher LCI and maximum quantum yield than plants in the other treatments. Plants grown under the red and blue PSN had increased leaf spectral reflectance indices compared to plants in the other treatments, which resulted in the highest levels of antioxidant scavenging enzymes, ascorbic acid (AsA), proline, and glycine betaine, and the lowest levels of H2O2. These findings demonstrate that increasing light in the red and far-red or blue portions of the spectrum by using PSN alters the photosynthetic and/or antioxidant responses of V. planifolia and increasing red and far-red light by using red PSN can also accelerate plant growth, possibly due to higher photosynthesis. •Red photoselective shade netting (PSN) increased nocturnal net CO2 assimilation and growth of Vanilla planifolia•Blue PSN increased chlorophyll content and maximum quantum yield of photosystem II•Red or blue PSN increased leaf antioxidant activity