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Peanut sprouts have recently been reported to be rich in some nutrients, including vitamin C, resveratrol, antioxidants, and folate, and are consumed as functional food. However, the effect of indirect plasma treatment, such as plasma-activated water (PAW), on the germination rate and growth of peanut remains largely unknown. Here, we evaluated the effect of PAW produced using a surface dielectric barrier discharge (SDBD) device on germination and vegetative growth in peanut. SDBD-generated PAW had significantly higher nitrate content than tap water (TW). Compared with the TW group, PAW treatment increased the germination rate of peanut seeds by more than twofolds at 3 days after planting; however, there was no significant difference in final germination rate between the PAW and TW groups at 7 days after seeding. In addition, PAW treatment significantly improved biomass-related morphological traits in peanut sprout compared with TW treatment. At the cellular level, PAW treatment increased cell size in the hypocotyl in both the horizontal (115%) and longitudinal (209%) directions, resulting in increased hypocotyl growth. Moreover, histological analysis showed that PAW treatment significantly enlarged parenchyma cell size in hypocotyl pith tissue but did not affect cell number. Overall, these results showed that PAW treatment improved seed germination and growth by enlarging parenchyma and epidermal cell size in hypocotyl, resulting in increased biomass in peanut sprouts. QRT–PCR results showed that auxin response and growth-related genes (AhARF5, AhIAA13, SAUR32, AhGI-13, AhGI-75, AhCUC3-12, and AhCUC3-65) were upregulated in the PAW treated condition at 6 days compared to the TW treated sprouts. [ABSTRACT FROM AUTHOR]

The quarantine bacterium Xylella fastidiosa was first detected in Salento (Apulia, Italy) in 2013 and caused severe symptoms in olives, leading to plant death. The disease, named Olive Quick Decline Syndrome (OQDS), is caused by the strain "De Donno" ST53 of the subspecies pauca of this bacterium (XfDD), which is spread by the insect Philaenus spumarius. The epidemic poses a serious threat to the agricultural economy and the landscape, as X. fastidiosa infects several plant species and there is yet no recognized solution. Research on OQDS is focused on finding strategies to control its spread or mitigate its symptoms. As a perspective solution, we investigated the efficacy of the low-temperature plasma and plasma-activated water to kill bacterial cells. Experiments were conducted in vitro to test the biocidal effect of the direct application of a Surface Dielectric Barrier Discharge (SDBD) plasma on bacteria cells and Plasma Activated Water (PAW). PAW activity was tested as a possible biocidal agent that can move freely in the xylem network paving the way to test the strategy on infected plants. The results showed a high decontamination rate even for cells of XfDD embedded in biofilms grown on solid media and complete inactivation in liquid culture medium. [ABSTRACT FROM AUTHOR]

The quarantine bacterium Xylella fastidiosa was first detected in Salento (Apulia, Italy) in 2013 and caused severe symptoms in olives, leading to plant death. The disease, named Olive Quick Decline Syndrome (OQDS), is caused by the strain “De Donno” ST53 of the subspecies pauca of this bacterium (XfDD), which is spread by the insect Philaenus spumarius. The epidemic poses a serious threat to the agricultural economy and the landscape, as X. fastidiosa infects several plant species and there is yet no recognized solution. Research on OQDS is focused on finding strategies to control its spread or mitigate its symptoms. As a perspective solution, we investigated the efficacy of the low-temperature plasma and plasma-activated water to kill bacterial cells. Experiments were conducted in vitro to test the biocidal effect of the direct application of a Surface Dielectric Barrier Discharge (SDBD) plasma on bacteria cells and Plasma Activated Water (PAW). PAW activity was tested as a possible biocidal agent that can move freely in the xylem network paving the way to test the strategy on infected plants. The results showed a high decontamination rate even for cells of XfDD embedded in biofilms grown on solid media and complete inactivation in liquid culture medium.