Influence of Exogenous Hydrogen Peroxide on Plant Physiology, Leaf Anatomy and Rubisco Gene Expression of the Ficus deltoidea Jack var. Deltoidea

Abstract

This study was carried out to investigate the regulatory effects of hydrogen peroxide (H2O2) on the growth, photosynthesis, biochemical properties, leaf anatomy and Rubisco gene expression in Ficus deltoidea var. deltoidea, a slow-growing medicinal herb. Results showed that 20-mM H2O2 treatment increased plant height, net photosynthetic rate, stomatal conductance and chlorophyll content of the plants by 10%, 20%, 127% and 57%, respectively, than a control plant. In addition, 20 mM H2O2 treatment significantly increased the carotene, total phenolic, total flavonoid and total sugar content than the control plant. The applications of H2O2 did not produce any negative effects on the leaf area, chlorophyll fluorescence, quantum yield or antioxidant activity of F. deltoidea plants. In regard to leaf anatomy, it was observed that the applications of H2O2 at 15 mM significantly improved cellular structure, leaf veins and promoted cell proliferation. Treated leaves developed a palisade layer, thickened leaf surface, the widest stomatal openings and a well-developed vascular bundle when compared to the control plant. Employing reverse transcription polymerase chain reaction (RT-PCR), the study showed that the Rubisco gene was expressed at a higher level in 15 mM H2O2 treatments than in 20 mM H2O2 treatments. The results indicate that H2O2 increased the Rubisco expression ratio up to 16-fold when compared to the untreated plants. It was conclusive that spraying 15 mM and 20 mM H2O2 twice a week enhanced growth, photosynthesis, the stomatal aperture, improved leaf anatomy and helped to regulate the expression of the Rubisco gene.

Effects of Hydrogen Peroxide on In Vitro Cultures of Tea (Camellia sinensis L.) Grown in the Dark and in the Light: Morphology, Content of Malondialdehyde, and Accumulation of Various Polyphenols

“…All this testifies to its diverse regulatory role in the vital activity of plants. Recently, more and more studies have investigated the use of H 2 O 2 as a growth regulator and adaptogen in the cultivation of various crops, both in vivo and in vitro [ 5 , 66 ]. In the latter case, plant cell cultures are of particular interest as producers of pharmacologically valuable secondary metabolites, including phenolic ones [ 1 ].…”

“…The search for regulatory molecules that increase the resistance of plant cells to stress and the accumulation of biologically active substances (BAS) in them is of great interest to researchers [ 1 , 2 , 3 ]. These include hydrogen peroxide (H 2 O 2 ), which acts as a regulator, terminator, or stimulator of cell growth [ 4 , 5 ]. Its participation in the processes of fruit ripening, leaf and flower formation, and the regulation of the functioning of photosystems, stomatal apparatuses, intracellular homeostasis, and other metabolic processes has been reported [ 6 , 7 ].…”

Influence of Trichoderma harzianum and Bacillus thuringiensis with reducing rates of NPK on growth, physiology, and fruit quality of Citrus aurantifolia

“…The leaf clip was fixed in clean mature leaf tissue, and then chlorophyll content was shown within two seconds (Khandaker et al, 2018). Leaf stomatal conductance (mmol /m 2 s) was measured with a handheld leaf porometer according to the methods described by Jamaludin et al (2020).…”

Morphophysiology, growth indices, and fruiting of pumpkin in response to organic amendments

“…The chlorophyll content in the leaves was measured using a SPAD-502 meter as per the method described in Buang, Yusoff, Nashriyah and Khandaker (2018). Leaf stomatal conductance was measured with a handheld leaf porometer according to the methods described by Jamaludin et al (2020).…”

“…measured with a handheld leaf porometer according to the methods described by Jamaludin et al (2020).…”