Hypericum perforatum plant cells reduce Agrobacterium viability during co-cultivation

Plant recalcitrance is the major barrier in developing Agrobacterium-mediated transformation protocols for several important plant species. Despite the substantial knowledge of T-DNA transfer process, very little is known about the factors leading to the plant recalcitrance. Here, we analyzed the basis of Hypericum perforatum L. (HP) recalcitrance to Agrobacterium-mediated transformation using cell suspension culture. When challenged with Agrobacterium, HP cells swiftly produced an intense oxidative burst, a typical reaction of plant defense. Agrobacterium viability started to decline and reached 99% mortality within 12 h, while the plant cells did not suffer apoptotic process. This is the first evidence showing that the reduction of Agrobacterium viability during co-cultivation with recalcitrant plant cells can affect transformation

Plant products with antifungal activity. From field to biotechnology strategies

In this chapter, informations on the recent advances regarding antifungal activity of natural products obtained from plants collected directly from their natural habitat or from plant cell and organ, cultures have been reported. The biotechnological approaches could increase uniformity and predictability of the extracts and overcome problems associated with geographical, seasonal, and environmental variations. Human fungal pathogens are the cause of severe diseases associated with high morbidity and mortality. The major human fungal pathogens are Candida species, dermatophytes, Aspergillus species, and Cryptococcus neoformans. Side effects and resistance are frequently attributed to the current antifungal agents. Moreover, the treatments often require long-term therapy and are not resolving. Plants represent a source of antifungal agents, but up to date, the number of new phytochemicals reaching the market is very low. This review attempts to summarize the current status of botanical screening efforts, as well as in vitro and in vivo studies on antifungal activity of plant products. Despite the currently non-uniform regulatory framework in all the states, the plant-derived products are increasingly in demand for their effectiveness. The basic conclusion from these studies is that rigorous, well-designed clinical trials are needed to validate the effectiveness and safety of plant extracts for their use as antifungals