Comparative physiological and transcriptome analysis in cultivated and wild sugarcane species in response to hydrogen peroxide-induced oxidative stress.

BACKGROUND: Sugarcane is an important energy crop grown worldwide,supplementing various renewable energy sources. Cultivated and wild sugarcane species respond differently to biotic and abiotic stresses. Generally, wild species are tolerant to various abiotic stresses. In the present study, the physiological and molecular responses of cultivated and wild sugarcane species to oxidative stress at the transcriptional levels were compared. Transcriptional responses were determined using RNAseq. The representative RNA-seq transcript values were validated by reverse transcriptase quantitative polymerase chain reaction (RT-qPCR) and confirmed through physiological responses. RESULTS: Oxidative stress causes leaf-rolling and -tip drying in cultivated sugarcane, but the wild species are tolerant. Higher chlorophyll fluorescence was observed in the wild species than that in the cultivated varieties under stress. Wild species can maintain a higher chlorophyll stability index than the cultivated species, which was confirmed by the lower transcripts of the chlorophyllase gene in the wild species than that in the cultivated variety. Transcription factor genes (NAC, MYB, and WRKY) were markedly expressed in response to oxidative stress, revealing their involvement in stress tolerance. The analysis revealed synchronized expression of acetyl-transferase, histone2A, cellulose synthase, and secondary cell wall biosynthetic genes in the wild species. The validation of selected genes and 15 NAC transcription factors using RT-qPCR revealed that their expression profiles were strongly correlated with RNA-seq. To the best of our knowledge, this is the first report on the oxidative stress response in cultivated and wild sugarcane species. CONCLUSION: Physiological and biochemical changes in response to oxidative stress markedly differ between cultivated and wild sugarcane species. The differentially expressed stress-responsive genes are grouped intothe response to oxidative stress, heme-binding, peroxidase activity, and metal ion binding categories. Chlorophyll maintenance is a stress tolerance response enhanced by the differential regulation of the chlorophyllase gene.There is a considerable difference in the chlorophyll stability index between wild and cultivated varieties. We observed a substantial regulation of secondary wall biosynthesis genes in the wild species compared with that in the cultivated variety, suggesting differences in stress tolerance mechanisms.

Significant action of Tridax procumbens L. leaf extract on reducing the TNF-α and COX-2 gene expressions in induced inflammation site in Swiss albino mice.

The leaves of traditionally used herbal plant Tridax procumbens L. contain lots of phytochemicals having potency to reduce inflammation. In this study, the ethanol extract of the leaves of Tridax procumbens L. was analysed for the phytochemicals by GC-MS. The anti-inflammatory activity was then studied with the extract of 10, 50, and 100 mg/kg b.wt in carrageenan-induced mice model by measuring the inflammatory oedema and by analysing the histopathology. The mRNA expression levels of TNF-α and COX2 genes were studied in the inflammatory site to explore the molecular action by reverse transcription PCR and qPCR analyses. A significant (P ≤ 0.01) reduction in mice paw inflammation and a recovered histology were observed in treated groups when compared to control group in 24 h. The RT-PCR results showed a significant (P ≤ 0.01) decrease in the expression levels of TNF-α and COX2 in terms of band density in treated mice compared to control group. The qPCR RQ values also were decreased in treated groups with respect to increasing doses (RQ values of 18.985 ± 0.230, 12.140 ± 1.121, 6.718 ± 0.807 for TNF-α and 15.583 ± 1.043, 7.725 ± 1.013, 5.075 ± 0.615 for COX2, respectively for the three doses) in comparison with the control group (TNF-α 27.107 ± 2.254, COX2 20.626 ± 1.477). Tridax procumbens L. can be, thus, used for the development of a safe, natural, anti-inflammatory drug as it showed a strong inhibitory action on inflammation by acting at molecular level.

Ameliorating effect of lipo-ATRA treatment on the expression of TIG3 and its suppressing effect on PPARγ gene expression in lung cancer animal model.

This study aimed to find out the molecular therapeutic effect of lipo-ATRA on tumour suppressor TIG3 and cell proliferative biomarker PPARγ in B (a) P-induced lung cancer model. In RT-PCR study, ATRA- and lipo-ATRA-treated mice samples showed relatively higher TIG3 expression and decreased PPARγ expression (Band density) than cancer control. Among treatments, lipo-ATRA showed vital effect than free ATRA by enhancing TIG3 and decreasing PPARγ. The qPCR results also showed significant (p ≤ 0.05) difference in both TIG3 and PPAR (RQ values of TIG3, lipo-ATRA 23.85 ± 1.29; free ATRA 10.43 ± 1.81 and for PPARγ, lipo-ATRA 4.707 ± 1.21; free ATRA 15.78 ± 2.34). From this, we conclude that liposomal ATRA formulation is most preferable for prolonged delivery of ATRA at targeted site to favour molecular action. It implies that the therapeutic effect of lipo-ATRA in lung cancer was exhibited by ameliorating the TIG3 expression and by suppressing the expression of PPARγ.