Effect of mycorrhizal inoculation and soluble phosphorus fertilizer on growth and phosphorus uptake of pearl millet

Six mycorrhizal fungi were tested as inoculants for pearl millet (Pennisetum americanum Leeke) grown in pots maintained in a greenhouse. VAM fungi varied in their ability to stimulate plant growth and phosphorus uptake. Inoculation withGigaspora margarita, G. calospora andGlomus fasciculatum increased shoot drymatter 1.3 fold over uninoculated control. In another pot trial, inoculation withGigaspora calospora andGlomus fasciculatum resulted in dry matter and phosphorus uptake equivalent to that produced by adding phosphorus at 8 kg/ha. The influence of inoculatingGigaspora calospora on pearl millet at different levels of phosphorus fertilizer (0 to 60 kg P/ha) as triple superphosphate in sterile and unsterile alfisol soil was also studied. In sterile soil, mycorrhizal inoculation increased dry matter and phosphorus uptake at levels less than 20 kg/ha. At higher P levels the mycorrhizal effect was decreased. These studies performed in sterilized soil suggest that inoculation of pearl millet with efficient VAM fungi could be extremely useful in P deficient soils. However, its practical utility depends on screening and isolation of fungal strains which perform efficiently in natural (unsterilized) field conditions

The PSD95–nNOS interface: a target for inhibition of excitotoxic p38 stress-activated protein kinase activation and cell death

The stress-activated protein kinase p38 and nitric oxide (NO) are proposed downstream effectors of excitotoxic cell death. Although the postsynaptic density protein PSD95 can recruit the calcium-dependent neuronal NO synthase (nNOS) to the mouth of the calcium-permeable NMDA receptor, and depletion of PSD95 inhibits excitotoxicity, the possibility that selective uncoupling of nNOS from PSD95 might be neuroprotective is unexplored. The relationship between excitotoxic stress–generated NO and activation of p38, and the significance of the PSD95–nNOS interaction to p38 activation also remain unclear. We find that NOS inhibitors reduce both glutamate-induced p38 activation and the resulting neuronal death, whereas NO donor has effects consistent with NO as an upstream regulator of p38 in glutamate-induced cell death. Experiments using a panel of decoy constructs targeting the PSD95–nNOS interaction suggest that this interaction and subsequent NO production are critical for glutamate-induced p38 activation and the ensuing cell death, and demonstrate that the PSD95–nNOS interface provides a genuine possibility for design of neuroprotective drugs with increased selectivity

Cowpea-Group Rhizobium In Soils Of The Semiarid Tropics

Population of "cowpea-group" Rhizobium in fields at ICRISAT were estimated by the most probable number(MPN) method using siratro (Macropulium atropurpureum) as host. There was usually a large variability in Rhizobium numbers between sampling sites in the same Held. The populations were more consistent in Alfisols (range from 104 to 3 x 105 /g soil) than in Vertisols (0 to 106 /g soil) and decreased with depth. In paddy fields, the numbers were very low. Pigeonpea cultivars ICP-7332 (small seeded) and ICP-1 (medium sized), grown in test tubes, could also be used for the MPN method. In four of five soils tested, counts with pigeonpea as host were less than when siratro was used

Rhizobium-induced leaf roll in pigeonpea [Cajanus cajan (L.) Millsp.]

The formation of nodules on legume roots by Rhizobium usually has a beneficial effect on plant growth because nitrogen is fixed in the nodules and transferred to other parts of the plant..