Responses of He-Ne laser irradiation on agronomical characters and chlorogenic acid content of brinjal (Solanum melongena L.) var. Mattu Gulla

The elicitation effects of diode and He-Ne laser irradiations on the alleviation of nutrient-deficiency induced damage in anthocyanin-producing red-fleshed apple cell suspension

PURPOSE

We explored the elicitation role of the laser irradiations on the alleviation of nutrient-deficiency induced damage in anthocyanin-producing red-fleshed apple cell suspension in continuous production of anthocyanin.

METHODS

Anthocyanin-producing red-fleshed apple cells were irradiated by 4 intensity levels of red He-Ne (RHNL) and blue diode (BDL) lasers for 20 min.

RESULTS

Nutrient deficiency indicated negative effect on total soluble proteins (TSP), superoxidase dismutase (SOD) activity, and total phenolics content (TPC) while it displayed a positive effect on malondialdehyde (MDA), total flavonoids content (TFC), O2-, H2O2-, and lipoxygenase (LOX) and polyphenol oxidase (PPO) activities in light controls, illustrating oxidative stress. The laser irradiations on suspension cells indicated variable effects on measured parameters and were time of growth-, levels of intensity-, and laser type-dependent. Likewise, the elicitation effects of lasers relied on a critical threshold among ROS generation and antioxidative system which determines the fate of cells against oxidative stress. The same trend was displayed by RHNL at 6.46 mWcm-2 intensity and BDL at 13.73 mWcm-2. These intensities resulted in a significant increase in SOD, APX, POD, and CAT activities and TSP, TPC, TFC, proline, and glycine betaine accumulation, while induced decrease in LOX, and PPO activities and MDA, and ROS generation, alleviating cellular injury from prolonged nutrient deficiency by diminishing lipid peroxidation and oxidative damages of cell membrane.

CONCLUSION

Results suggested that lasers application on mitigating nutrient deficiency stress relied on establishing a suitable balance between ROS generation and antioxidative system, which enables the nutrient-starved anthocyanin-producing cells to continuously produce anthocyanin.

He-Ne laser accelerates seed germination by modulating growth hormones and reprogramming metabolism in brinjal

A plant’s ability to maximize seed germination, growth, and photosynthetic productivity depends on its aptitude to sense, evaluate, and respond to the quality, quantity, and direction of the light. Among diverse colors of light possessing different wavelengths and red light shown to have a high impact on the photosynthetic and growth responses of the plants. The use of artificial light sources where the quality, intensity, and duration of exposure can be controlled would be an efficient method to increase the efficiency of the crop plants. The coherent, collimated, and monochromatic properties of laser light sources enabled as biostimulator compared to the normal light. The present study was attempted to use the potential role of the He–Ne laser as a bio-stimulator device to improve the germination and growth of brinjal and to investigate the possible interactions of plant and laser photons. A substantial enhancement was observed in germination index, germination time and seed vigor index of laser-irradiated than control groups. The enhanced germination rate was correlated with higher GA content and its biosynthetic genes whereas decreased ABA content and its catabolic genes and GA/ABA ratio were noted in laser-irradiated groups during seed germination than control groups. Further the expression of phytochrome gene transcripts, PhyA and PhyB1 were upregulated in laser-irradiated seedlings which correlate with enhanced seed germination than control. Elevated levels of primary metabolites were noted in the early stages of germination whereas modulation of secondary metabolites was observed in later growth. Consequently, significantly increased photosynthetic rate, stomatal conductance, and transpiration rate was perceived in laser-irradiated seedlings compare with control. The current study showed hormone and phytochrome-mediated mechanisms of seed germination in laser-irradiated groups along with the enhanced photosynthetic rate, primary and secondary metabolites.

Red laser-mediated alterations in seed germination, growth, pigments and withanolide content of Ashwagandha [Withania somnifera (L.) Dunal]

Withania somnifera (L.) Dunal, generally well-known as Ashwagandha, is part of Indian traditional medicinal systems like Ayurveda, Siddha, and Unani for over 3000 years for treating an array of disorders. The chief bioactive component of this plant is the withanolides, a group of C₂₈-steroidal lactone triterpenoids. These compounds are present in very low concentrations and hence cell culture methods have been used to enhance their production. Low-level laser irradiation has been reported to have elicited the seed germination, agronomical characters, biosynthesis of bioactive compounds in some plants. Therefore, the objective of the study was to investigate the effect of red (He-Ne) laser irradiation on seed germination, growth characters, pigment contents and withanolide content in W. somnifera. The seeds were inoculated onto two different combinations of Murashige and Skoog (MS) media and incubated for germination. The highest germination percentage was observed in ½ MS with pH 6.5 and GA₃ presoaking followed by ½ MS with different pH. Four different doses of Helium-Neon (He-Ne) laser (10, 15, 20 and 25 J/cm²) were used to irradiate the seeds at 632.8 nm and germinated in vitro on ½ MS with pH 6.5. The maximum germination percentage, 63.88% was noted from seeds irradiated with 25 J/cm² (P = 0.04). The highest total length of 13.33 cm was observed in the seedlings irradiated with 25 J/cm² groups (P = 0.008). The highest total chlorophyll content of 329.5 μg/g fresh weight (FW) was observed for seedlings irradiated with 15 J/cm² (P = 0.02) and the highest carotenoid content of 49.6 μg/g FW was observed for 25 J/cm² treated seedlings. Further, primary root length was measured and found to be highest (11.14 cm) in seedlings irradiated with 10 J/cm² and the highest number of lateral roots were observed for 15 and 25 J/cm² groups. The significant amount of Withanolide A (WA) 0.52 μg/g dry weight (DW) and 0.60 μg/g DW was noted in 15 (P = 0.01) and 20 J/cm² (P = 0.002) groups, respectively than control. The present investigation thus reveals the positive impact of red laser on the germination of seeds, growth characters and withanolide contents under in vitro environment.

ROS-dependent DNA damage and repair during germination of NaCl primed seeds

Reactive oxygen species (ROS) generated during rehydration of seeds is a major source of cellular damage. Successful germination depends on maintaining the oxidative window and ability of the cells to repair the DNA damage accumulated during seed developmental process, maturational drying, and germination. We explored the role of DNA damage, repair, cell cycle progression and antioxidant machinery in germination of seeds of Solanum melongena L. primed with 0, 320, 640 and 1200 mM sodium chloride (NaCl). The expression of antioxidant genes such as ascorbate peroxidase (APX), superoxide dismutase (SOD), catalase2 (CAT2), and glutathione reductase (GR) was upregulated to maintain the oxidative window required for germination in seeds treated with 320 mM NaCl. ROS generated upon treatment with 320 mM NaCl resulted in minimal DNA damage and activated non-homologous end joining (NHEJ) and mismatch repair (MMR) pathway genes such as KU70 and mutS homolog 2 (MSH2) respectively. Treatment with higher concentrations of NaCl resulted in increased DNA damage despite lower ROS, without evoking DNA repair mechanisms. Uncontrolled rehydration resulted in higher levels of ROS and DNA damage, but activation of homologous recombination (HR) pathway gene, Nijmegen breakage syndrome 1 (NBS1), and genes involved in repairing oxidized guanine, such as oxoguanine DNA glycosylase (OGG1) and proliferating cell nuclear antigen (PCNA). In summary, controlled rehydration with 320 mM NaCl decreased the DNA damage, reactivated the antioxidant and DNA repair machinery, and cell cycle progression, thereby enhancing the seed germination.

From nutrition to medicine: Assessing hemorrhoid healing activity of Solanum melongena L. via in vivo experimental models and its major chemicals

ETHNOPHARMACOLOGICAL RELEVANCE

Solanum melongena L. (eggplant) is used for treatment of rheumatism, beriberi, itching, toothache, bleeding, asthma, bronchitis, cholera, neuralgia and hemorrhoids in traditional medicine (Turkish, Chinese, and Indian). Hemorrhoids from these diseases, are common illness in all over the world, which are treated with various approaches including ethnobotanicals.

AIM OF THE STUDY

This study aimed to evaluate the anti-hemorrhoidal activity of eggplant, an edible plant, which is commonly utilized around the world.

MATERIALS & METHODS

In vivo anti-hemorrhoidal activity of the methanolic extract prepared from eggplant was evaluated by experimental hemorrhoid model, subsequently histological and biochemical analysis. Hemorrhoid, which was induced by applying croton oil to the anal area of the rats. Furthermore, the extract was screened for anti-inflammatory activity which is based on the inhibition of acetic acid-induced increase in capillary permeability. The healing potential was comparatively assessed with a reference Pilex® tablet and cream. Phytochemical analysis performed by HPLC. The amount of the major phenolic compound (chlorogenic acid) in extract was found by using HPLC method.

RESULTS

Histological and biochemical analysis demonstrated that eggplant extract is highly effective against hemorrhoid in comparison to the controls and the commercial preparation. In addition, the methanolic extract demonstrated significant inhibitory effect on acetic acid-induced increase in capillary permeability. The phytochemical studies identified major compound as chlorogenic acid (2.86%) by liquid chromatography.

CONCLUSION

The eggplant calyxes, not edible, are easy to reach, by products/vast from the food sources. This is the first scientific evidence revealing that the eggplant extract has significant anti-hemorrhoidal and anti-inflammatory activity.

Characterization of miRNAs and their target genes in He-Ne laser pretreated wheat seedlings exposed to drought stress

Drought stress is considered a critical environmental factor that negatively affects wheat growth and development, which causes considerable losses in wheat yields worldwide. More recently, numerous microRNAs (miRNAs) have been found to be involved in wheat responses to drought stresses. However, there is little information regarding the effects of He-Ne laser irradiation on the expression traits of miRNAs and their targets in wheat seedlings exposed to drought stress. In the current study, therefore, a combination of physiological and molecular approaches was used to assess the effect of He-Ne laser irradiation on the expression of miRNAs and their targets in wheat seedlings exposed to drought stress. Our results demonstrated that drought stress significantly reduced plant height, root length, shoot and root fresh weight, relative water content, the expression level and activity of superoxide dismutase (SOD), enhanced malondialdehyde (MDA) concentration in the wheat seedlings. However, He-Ne laser irradiation significantly enhanced the activities of SOD, ascorbate peroxidase (APX), peroxidase (POD) and relative water content, and reduced MDA concentration of seedlings by regulating gene expression for SOD, POD, APX. In addition, in comparison with drought stress alone, miR160, miR164 and miR398 transcripts were down-regulated, and expression levels of its targets auxin response factor (ARF22), NAC domain transcription factor and Cu/Zn superoxide dismutases (CSD) were up-regulated in He-Ne laser irradiated seedlings exposed to drought stress. These results suggested that He-Ne laser irradiation could possible protection of drought stress, at least partially, by increasing the transcript levels and activities of SOD, POD and APX, and decreasing the transcript levels of miR160, miR164 and miR398. To the best of our knowledge, this is the first study to present biochemical and molecular evidence supporting the effect of He-Ne laser irradiation on the alleviation of drought stress in wheat seedlings mediated by miRNA expression.