Shoot

About: Shoot is a research topic. Over the lifetime, 32188 publications have been published within this topic receiving 693348 citations.

Effects of arbuscular mycorrhiza inoculation on plant growth, biological and physiological parameters and mineral nutrition in pepper grown under different salinity and p levels.

Abstract: A study was conducted in a greenhouse, to investigate the effects of arbuscular mycorrhizal fungi (Glomus intraradices), soil salinity and P availability on growth (leaf area and dry weight), nutrient absorption and ion leakage, chlorophyll, soluble sugar and proline content and alkaline phosphatase activity of pepper plants (Capsicum annuum L) Plants were grown at four levels of salinity (0, 50, 100 and 200 mM NaCl) and two P levels (10 and 40 mg kg -1 ) Colonisation was 80% to 51% in non-stressed and high salt-stressed plants, respectively The mycorrhizal dependency was high and only reduced at the higher salinity level Mycorrhizal plants maintained greater root and shoot biomass at all salinity levels compared to non-mycorrhizal plants, regardless the P level Interactions between salinity, phosphorous and mycorrhizae were significant for leaf area, root and shoot dry mass Non-mycorrhizal plants accumulated higher Na and lower K and P compared to mycorrhizal plants The cell membrane integrity was greater in mycorrhizal plants than in non-mycorrhizal ones The proline content increases with increasing salt stress and was significantly higher in leaves than in roots The results indicate that the mycorrhizal inoculation is capable of alleviating the damage caused by salt stress conditions on pepper plants, to maintaining the membranes stability and plant growth, and this could be related to P nutrition

Physiological response of common bean (Phaseolus vulgaris L.) seedlings to salinity stress

Abstract: The effect of salinity stress on five cultivars of common bean: Bassbeer, Beladi, Giza 3, HRS 516 and RO21 were evaluated on a sand/peat medium with different salinity levels (0, 50 and 100 mM NaCl) applied 3 weeks after germination for duration of 10 days. Salinity had adverse effects not only on the biomass yield and relative growth rate (RGRt), but also on other morphological parameters such as plant height, number of leaves, root length and shoot/root weight ratio. Photosynthesis, transpiration rate and stomatal conductance were adversely affected in all cultivars. Leaf osmotic potential and leaf turgor varied significantly among cultivars and salt levels. The interaction between cultivars and salt levels for photosynthesis, leaf osmotic potential and leaf turgor was highly significant at day 10 of salt treatment. The Na uptake among the cultivars varied in the order: HRS 516 highest survival rate and no symptoms of salt stress. RO21 was the most susceptible to salinity as it showed severe symptoms of salt stress and very low survival rate.

Factors affecting Agrobacterium-mediated transformation in Citrus and production of sour orange (Citrus aurantium L.) plants expressing the coat protein gene of citrus tristeza virus

Abstract: Factors influencing transformation frequencies using the Agrobacterium-mediated protocol developed for Citrus seedling internodal stem segments in this laboratory were evaluated, with particular emphasis on decreasing the numbers of ``escape'' shoots produced. Although the use of a wild-type ``shooty'' Agrobacterium strain allowed relatively high frequencies of β-glucuronidase positive (GUS+) shoots to be produced, none of the shoots were free of wild-type T-DNA and would not root. Both use of a liquid medium/kanamycin overlay and horizontal placement of stem segments increased the efficiency of kanamycin selection. Wounding via particle bombardment prior to Agrobacterium inoculation did not increase transformation frequencies. The concentration of benzyladenine (BA) in the regeneration/selection medium inversely influenced the numbers of shoots that regenerated and the subsequent ability of the shoots to root. Regeneration in the presence of kanamycin also influenced the ability of shoots to root. Many of the shoots that regenerated on selection medium were chimeric for GUS expression, and plants established from such shoots ranged from non-staining to solidly staining for GUS. However, solidly transformed plants with integrated T-DNA were obtained, and these plants have maintained the expression of transgenes over several years. The transgenic plants include ones of sour orange (C. aurantium L.) and Key lime (C. aurantifolia (Christm.) Swing.), two species not previously transformed, and have integrated and express the coat protein gene of citrus tristeza virus. This is the first report of a potentially agriculturally important transgene being expressed in Citrus.