Light-emitting diodes (LED) increase the stomata formation and chlorophyll content in Musa acuminata (AAA) ‘Nanicão Corupá’ in vitro plantlets

Abstract

Micropropagation of banana by means of different morphogenetic routes is an important source of genetically uniform, pest-and disease-free planting materials of Musa spp. Morphogenesis of in vitro grown plants are affected by light quality, light quantity and photoperiod. Light-emitting diode (LED) lighting systems have several unique advantages, including their peak spectral output, which closely coincides with the red absorption peak of chlorophyll and the reported wavelengths for maximum photosynthetic efficiency. The present study was aimed to investigate the effect of two LED lighting treatments (white LED and deep red/white LED) compared to conventional fluorescent lamps on the stomata formation and chlorophyll (Chl) levels in micropropagated banana plantlets through organogenesis. Both LED lighting evaluated increased the levels of total Chl, Chl-a and Chl-b in banana in vitro plantlets, indicating no statistical difference between them, but being higher then plantlets subjected to fluorescent lamps. The number of stomata was also increased equally by both LED lighting treatments, indicating increased formation of stomata in both abaxial and adaxial leaf surfaces when compared to fluorescent lamps. Although all treatments presented 100 % survival in the acclimatization phase, LED lighting show promising for micropropagation of banana due to its known superior light quality, low energy consumed, little heat generated and long operating lifetime.

Supplementary Light Source Affects the Growth and Development of Codonopsis lanceolata Seedlings

“…The stomatal size and density are indicators of plant adaptation and acclimation to environments [ 48 ]. The development of stomatal properties in tender leaves are largely affected by the light spectrum [ 11 , 49 ]. We found that the stomatal density, aperture, and conductance were highly enhanced in leaves developed in LED-mix, followed by those in LED-w, and were largely decreased for leaves in FR.…”

“…The changes of the stomatal density were related to the proportion of red light, and the changes in the stomatal aperture were highly related to the proportion of blue light, as well as the summed proportion of blue and red lights. The stomatal density was affected by the light quality, but the roles of monochromatic lights remained controversial since different studies reported different results [ 10 , 11 , 49 , 50 ]. On the other hand, the effect of monochromatic lights on the stomatal aperture is relatively clear.…”

“…On the other hand, the effect of monochromatic lights on the stomatal aperture is relatively clear. It’s reported that blue light is more efficient in regulating the stomatal opening [ 11 , 49 ] and stomatal aperture is larger for plants under blue LEDs than for plants under red and white LEDs [ 10 , 51 ]. A weak blue light superimposed on red light induced a very rapid increase in the stomatal aperture in rice [ 52 ] and red light enhanced the blue light response of Paphiopedilum [ 53 ].…”

“…An increasing proportion of blue light also increased the stomatal conductance and the net photosynthetic rate in Alternanthera brasiliana [ 8 ]. The stomata provides plants with a dominant means to adjust to environmental changes [ 11 ]. Highly dense, small stomata is the best way to attain the highest stomatal conductance values at low atmospheric CO 2 concentrations [ 54 ].…”

“…The leaf structure, thicknesses of the palisade mesophyll cells, spongy tissues, and epidermis vary with the light spectrum [ 8 , 9 ]. Additionally, the development of the stomata and its properties can be largely affected by the light environment [ 10 , 11 ]. Light quality alters photosynthesis by changing the photosynthetic apparatus activity and the expression and/or the activity of photosynthetic enzymes [ 6 ].…”