Glutathione Restores Hg-Induced Morpho-Physiological Retardations by Inducing Phytochelatin and Oxidative Defense in Alfalfa.

Mercury (Hg) is toxic to plants, but the effect of glutathione in Hg alleviation was never studied in alfalfa, an important forage crop. In this study, Hg toxicity showed morphological retardation, chlorophyll reduction, and PSII inefficiency, which was restored due to GSH supplementation in alfalfa plants treated with Hg. Results showed a significant increase of Hg, but Fe and S concentrations substantially decreased in root and shoot accompanied by the downregulation of Fe (MsIRT1) and S (MsSultr1;2 and MsSultr1;3) transporters in roots of Hg-toxic alfalfa. However, GSH caused a significant decrease of Hg in the shoot, while the root Hg level substantially increased, accompanied by the restoration of Fe and S status, relative to Hg-stressed alfalfa. The subcellular analysis showed a substantial deposition of Hg in the root cell wall accompanied by the increased GSH and PC and the upregulation of MsPCS1 and MsGSH1 genes in roots. It suggests the involvement of GSH in triggering PC accumulation, causing excess Hg bound to the cell wall of the root, thereby reducing Hg translocation in alfalfa. Bioinformatics analysis showed that the MsPCS1 protein demonstrated one common conserved motif linked to the phytochelatin synthase domain (CL0125) with MtPCS1 and AtMCS1 homologs. These in silico analysis further confirmed the detoxification role of MsPCS1 induced by GSH in Hg-toxic alfalfa. Additionally, GSH induces GSH and GR activity to counteract oxidative injuries provoked by Hg-induced H2O2 and lipid peroxidation. These findings may provide valuable knowledge to popularize GSH-derived fertilizer or to develop Hg-free alfalfa or other forage plants.

Importance of Mineral Nutrition for Mitigating Aluminum Toxicity in Plants on Acidic Soils: Current Status and Opportunities.

Aluminum (Al) toxicity is one of the major limitations that inhibit plant growth and development in acidic soils. In acidic soils (pH < 5.0), phototoxic-aluminum (Al3+) rapidly inhibits root growth, and subsequently affects water and nutrient uptake in plants. This review updates the existing knowledge concerning the role of mineral nutrition for alleviating Al toxicity in plants to acid soils. Here, we explored phosphorus (P) is more beneficial in plants under P-deficient, and Al toxic conditions. Exogenous P addition increased root respiration, plant growth, chlorophyll content, and dry matter yield. Calcium (Ca) amendment (liming) is effective for correcting soil acidity, and for alleviating Al toxicity. Magnesium (Mg) is able to prevent Al migration through the cytosolic plasma membrane in root tips. Sulfur (S) is recognized as a versatile element that alleviates several metals toxicity including Al. Moreover, silicon (Si), and other components such as industrial byproducts, hormones, organic acids, polyamines, biofertilizers, and biochars played promising roles for mitigating Al toxicity in plants. Furthermore, this review provides a comprehensive understanding of several new methods and low-cost effective strategies relevant to the exogenous application of mineral nutrition on Al toxicity mitigation. This information would be effective for further improvement of crop plants in acid soils.

Genotypic variation of Agrobacterium-mediated transformation of Italian ryegrass

In the present study, genotypic variation of Agrobacterium-mediated transformation of Korean Italian ryegrass has been evaluated. Mature seed-derived calli of seven cultivars were inoculated and co-cultured with Agrobacterium tumefaciens carrying the binary vector pCAMBIA1301, which contains a reporter gene (gus) and a plant selectable marker gene conferring resistance to hygromycin (hpt) in the T-DNA region. The effects of several factors such as callus type and callus age on transformation effectiveness and the expression of the GUS gene were investigated. The highest transformation effectiveness (6.7 percent) was obtained with the Hwasan 101 cultivar when 9-week-old calli (type-I) were inoculated with Agrobacterium. The overall transformation rates of the examined cultivars ranged from 0.4 percent to 6.7 percent. GUS histochemical assays, PCR, and southern analysis of transgenic plants demonstrated that transgenes were successfully integrated into the genome of Italian ryegrass. Thus, evaluation of transformation effectiveness and selection of a suitable cultivar of Italian ryegrass may improve molecular breeding of this species.

Surgical Treatment of Burn Induced Helical Keloid with Excision and Full-Thickness Skin Grafting

Burn induced helical keloid is usually manifested by the severe disfigurement. The satisfactory reconstruction of the helical rim has not been achieved by the methods such as full thickness skin grafting(FTSG), core extirpation, and simple excision combined with intralesional steroid injection. In treatment with FTSG, the frequent failure of skin graft in the helical rim is due to the lack of adequate vascular supply in the recipient bed and the exposed helical cartilage after keloid excision. However, if the recipient bed with rich vascularity is widen and sufficient to maintain the viability of the graft, FTSG is the best method that leaves less donor morbidity and is able to reconstruct the natural appearance of helix. We proposed that the improved survival of skin graft could be achieved by better vascular supply by the deepithelialization of the surrounding normal skin after keloid excision. Five helical burn keloids and hypertrophic scars were reconstructed by the method of excision and FTSG. There were no recurrence and the results showed good texture and similar skin color. Excision of scar and FTSG is a satisfactory method to treat helical burn keloid.

An Ectopic Pleomorphic Adenoma in the Superficial Subcutaneous Layer of the Preauricular Area

Pleomorphic adenoma is a benign tumor originated from the mature salivary tissue. Ectopic pleomorphic adenoma is defined as an unusual presentation of pleomphic adenoma in other sites except the major salivary gland and the minor salivary gland. Ectopic pleomorphic adenoma was found in the soft tissue of the neck, in the skin of the external auditory canal, in the subcutaneous layer of the nose, and in the lymph node of the mediastinum. Ectopic pleomphic adenoma could appear due to the metastasis, the neoplastic degeneration of the ectopic salivary tissue, or the implantation after the surgery of a salivary gland tumor. We present a case of pleomorphic adenoma found in the superficial subcutaneous layer above the superficial musculoaponeurotic system(SMAS) of the preauricular area. The patient had no history of the surgery of the salivary tumor and no specific physical finding. We discussed the previous cases of ectopic salivary tissues and ectopic pleomorphic adenomas. No case of the ectopic salivary tissue nor ectopic pleomorphic adenoma in the superficial subcutaneous layer of the preauricular area has been reported. This case could be a rare presentation of the ectopic pleomorphic adenoma from the ectopic salivary tissue arising from the division of the parotid gland in early embryonic period.