According to an established concept, injury of the phloem triggers local sieve plate occlusion including callose-mediated constriction and, possibly, protein plugging of the sieve pores. Sieve plate occlusion can also be achieved by distant stimuli, depends on the passage of electropotential waves (EPWs), and is reversible in intact plants. The time-course of the wound response was studied in s...

Plants show varied cellular responses to salinity that are partly associated with maintaining low cytosolic Na(+) levels and a high K(+)/Na(+) ratio. Plant metabolites change with elevated Na(+), some changes are likely to help restore osmotic balance while others protect Na(+)-sensitive proteins. Metabolic responses to salt stress are described for two barley (Hordeum vulgare L.) cultivars, Sa...

According to an established concept, injury of the phloem triggers local sieve plate occlusion including callose-mediated constriction and, possibly, protein plugging of the sieve pores. Sieve plate occlusion can also be achieved by distant stimuli, depends on the passage of electropotential waves (EPWs), and is reversible in intact plants. The time-course of the wound response was studied in s...

The effects of exogenously applied gibberellic acid (GA(3)) or brassinolide (BL) on the H(+)-pumps and aquaporin in the vacuolar membrane of rice seedling leaf sheath were investigated. Antibodies against mung bean H(+)-PPase, the B subunit of V-ATPase, and radish tonoplast intrinsic protein (TIP) cross-reacted with the vacuolar membrane proteins of rice seedling leaf sheath. The results of imm...

The transport of salicylic acid (SA) was studied in cucumber (Cucumis sativus L.) using 14C-labeled benzoic acid that was injected in the cotyledons at the time of inoculation. Primary inoculation with tobacco necrosis virus (TNV) on the cotyledons led to an induction of systemic resistance of the first primary leaf above the cotyledon against Colletotrichum lagenarium as early as 3 d after ino...

Hydrogen peroxide (H2O2) has been implicated in many stress conditions. Control of H2O2 levels is complex and dissection of mechanisms generating and relieving H2O2 stress is difficult, particularly in intact plants. We have used transgenic tobacco with approximately 10% wild-type catalase activity to study the role of catalase and effects of H2O2 stress in plants. Catalase-deficient plants sho...

Extract of Toona sinensis (TS) has been reported to have various effects on cultured cell lines, including anti-proliferative activity in cancer cells. We have studied the effects of TS on various human oral squamous carcinoma cell lines (HOSCC), including UM1, UM2, SCC-4, and SCC-9. These cell lines were treated with TS leaf extract and screened for viability, apoptosis, necrosis, and apoptoti...

Lipid peroxidation was investigated in relation with the hypersensitive reaction in cryptogein-elicited tobacco leaves. A massive production of free polyunsaturated fatty acid (PUFA) hydroperoxides dependent on a 9-lipoxygenase (LOX) activity was characterized during the development of leaf necrosis. The process occurred after a lag phase of 12 h, was accompanied by the concomitant increase of ...