Morphological and physiological responses of rice seedlings to complete submergence (flash flooding).

Background And Aims: Reducing damage to rice seedlings caused by flash flooding will improve the productivity of rainfed lowland rice in West Africa. Accordingly, the morphological and physiological responses of different forms of rice to complete submergence were examined in field and pot experiments to identify primary causes of damage.

Methods: To characterize the physiological responses, seedlings from a wide genetic base including Oryza sativa, O.

Detection, isolation and characterization of a root-exuded compound, methyl 3-(4-hydroxyphenyl) propionate, responsible for biological nitrification inhibition by sorghum (Sorghum bicolor).

Nitrification results in poor nitrogen (N) recovery and negative environmental impacts in most agricultural systems. Some plant species release secondary metabolites from their roots that inhibit nitrification, a phenomenon known as biological nitrification inhibition (BNI). Here, we attempt to characterize BNI in sorghum (Sorghum bicolor).

Overexpression of monodehydroascorbate reductase in transgenic tobacco confers enhanced tolerance to ozone, salt and polyethylene glycol stresses.

Ascorbate (AsA) is a major antioxidant and free-radical scavenger in plants. Monodehydroascorbate reductase (MDAR; EC 1.6.

Identification and cloning of a submergence-induced gene OsGGT (glycogenin glucosyltransferase) from rice (Oryza sativa L.) by suppression subtractive hybridization.

A submergence-induced gene, OsGGT, was cloned from 7-day submerged rice (Oryza sativa L. plants, FR13A (a submergence-tolerant cultivar, Indica), using suppression subtractive hybridization and both 5'- and 3'-rapid amplification of cDNA ends (RACE). The full-length OsGGT cDNA contains 1,273 bp with an open reading frame of 1,140 bp (17-1,156) that encodes 379 amino acids.

Over-expression of ascorbate peroxidase in tobacco chloroplasts enhances the tolerance to salt stress and water deficit.

The role of APX (ascorbate peroxidase) in protection against oxidative stress was examined using transgenic tobacco plants. The full length cDNA, coding Arabidopsis thaliana L. APX fused downstream to the chloroplast transit sequence from A.

Cloning of a putative monogalactosyldiacylglycerol synthase gene from rice (Oryza sativa L.) plants and its expression in response to submergence and other stresses.

Suppression subtractive hybridization was used to construct a subtractive cDNA library from plants of non-submerged and 7-day-submerged rice (Oryza sativa L., FR13A, a submergence-tolerant cultivar). One clone of the subtractive cDNA library, S23, was expressed abundantly during submergence.

Blocking ethylene perception enhances flooding tolerance in rice seedlings.

Large areas of rainfed lowlands in South and Southeast Asia annually experience short durations of flash flooding during the rice-growing season, which dramatically affect plant survival and productivity. Submergence-intolerant cultivars usually show progressive leaf chlorosis, which could be triggered by ethylene produced during submergence. An ethylene inhibitor, 1-methyl cyclopropene (MCP), was used to evaluate the effect of ethylene on chlorophyll degradation and plant survival.