Light Spectral Composition Influences Structural and Eco-Physiological Traits of Solanum lycopersicum L. cv. ‘Microtom’ in Response to High-LET Ionizing Radiation

Abstract

This study evaluated if specific light quality (LQ) regimes (white fluorescent, FL; full-spectrum, FS; red-blue, RB) during plant growth modified morphological and photosynthetic traits of Solanum lycopersicum L. ‘Microtom’ plants irradiated at the dry seed stage with 25 Gy 48Ca ions (IR). The irradiation reduced plant size while it increased leaf dry matter content (LDMC) and relative water content (RWC) compared to the control. FS and RB light regimes determined a decrease of plant height and a rise of RWC compared to FL plants. The irradiation under FS and RB regimes favoured the development of dwarf plants and improved the leaf water status. Under the FL regime, irradiated plants showed reduced photosynthesis and stomatal conductance. The opposite behavior was observed in RB irradiated plants in which gas exchanges were significantly stimulated. RB regime enhanced Rubisco expression in irradiated plants also inducing anatomical and functional adjustments (i.e., increase of leaf thickness and incidence of intercellular spaces). Finally, 48Ca ions did not prevent fruit ripening and the achievement of the ‘seed-to seed’ cycle, irrespective of the LQ regime. Overall, the present study evidenced that RB light regime was the most effective in optimising growth and photosynthetic efficiency of ‘Microtom’ irradiated plants. These outcomes may help to develop proper cultivation protocols for the growth of dwarf tomato in Controlled Ecological Life Support Systems (CELSS).

Manipulation of light quality is an effective tool to regulate photosynthetic capacity and fruit antioxidant properties of Solanum lycopersicum L. cv. ‘Microtom’ in a controlled environment

“…A compact size characterizes the ‘Microtom’ cultivar, and the induction of further plant compactness may favour tomato growth in a high plant density condition or restricted volumes. Compared to FL, the higher intensityof blue wavelengths composing RB and RGB treatments may be responsible for the more compact size observed in these plants because blue wavelengths by inhibiting cell division and expansion act directly on plant morphogenesis, especially in the early stage of development ( Dougher & Bugbee, 2004 ; Nanya et al, 2012 ; Izzo et al, 2020 ; Vitale et al, 2021 ).…”

Comparative Analysis of the Effect of Carbon- and Titanium-Ions Irradiation on Morpho-Anatomical and Biochemical Traits of Dolichos melanophthalmus DC. Seedlings Aimed to Space Exploration

“…Ti-ion was chosen as, although it is considered to simulate GCR well, there is not much information on its acute effects on plants, while C-ion was considered as a reference radiation as it is widely used in experiments on plant biology. The doses utilized in our experiment, namely 1 Gy and 10 Gy, are considered low for plant organisms, and were specifically chosen to avoid detrimental outcomes and induce stimulatory effects on plants [3,33,41]. Therefore, the knowledge gained from this study may be useful to achieve a first evaluation of the radiation-induced morpho-anatomical and biochemical responses of eye bean seedlings, in order to include data on radio-resistance in the decision process for: (i) evaluating whether eye bean is a good candidate for food supplement in long term manned space missions in which plants would be exposed to chronic radiation; and (ii) defining cultivation requirements in BLSSs.…”

Light Quality Modulates Photosynthesis and Antioxidant Properties of B. vulgaris L. Plants from Seeds Irradiated with High-Energy Heavy Ions: Implications for Cultivation in Space

“…On the other hand, the seed irradiation with Ti-ion under RGB and RB regimes stimulated A N and g S compared to FL, determining, also in this case, an improvement of iWUE. In response to different LQ regimes during growth, leaves of irradiated plants have probably adopted adjustments in mesophyll traits and stomatal movements to improve photosynthesis and iWUE [ 45 ]. According to other authors, RB wavelengths, alone or supplemented with the green light that penetrates deeper inside the canopy, may have induced changes in leaf thickness, promoting the CO 2 diffusion within chloroplasts [ 56 , 62 , 63 , 64 , 65 , 66 ].…”

“…From this perspective, studying the interaction between space IR and light quality (LQ) is gaining interest in space research. Recent studies on crops evidenced that the interplay LQ/IR may elicit essential plant traits, such as dwarf growth, increased photosynthesis and nutritional value [ 44 , 45 ]. The present study aimed to deepen the knowledge of the interaction between high-LET (Linear Energy Transfer) ionizing radiation and LQ on chard ( B. vulgaris L. var.…”