Different abiotic stresses induce OsTZF1, a tandem CCCH-type zinc finger domain gene, in rice. Here, we report that transgenic rice plants overexpressing OsTZF1 under own promoter (POsTZF1:OsTZF1-OX [for overexpression]) transferred to soil showed normal growth similar to vector control plants. The POsTZF1:OsTZF1-OX produced normal leaves without any lesion mimic phenotype and exhibited normal seed setting. The POsTZF1:OsTZF1-OX plants showed significantly increased tolerance to salt and drought stresses and enhanced post stress recovery. Microarray analysis revealed a total of 846 genes up-regulated and 360 genes down-regulated in POsTZF1:OsTZF1-OX salt-treated plants. Microarray analysis of POsTZF1:OsTZF1-OX plants showed the regulation of many abiotic stress tolerance genes. These results suggest that OsTZF1-OX under own promoter show abiotic stress tolerance and produces no pleiotropic effect on phenotype of transgenic rice plant.
Lectins are unique glycoproteins that react with specific sugar residues on cell surfaces resulting in agglutination. They offer enormous applications in therapeutics, diagnostics, medicine, and agriculture. Rice lectins are naturally expressed during biotic and abiotic stresses suggesting their importance in stress resistance physiology. The objective of this study was to determine the presence and relative concentration of lectins in different accessions of rice obtained from IABGR/NARC Islamabad mainly originated from Pakistan. About 210 rice accessions including 02 local varieties and 05 transgenic seeds were screened for seed lectins using a hemagglutination (HA) assay with 5% Californian bred rabbits’ erythrocytes. A protein concentration of 3–8 mg/100 mg of seed flour was measured for all the rice accessions; the highest was 8.03 mg for accession 7600, while the lowest noted was 3.05 mg for accession 7753. Out of 210 accessions, 106 showed the highest HA activity. These 106 genotypes were further screened for titer analysis and specific activity. The highest titer and specific activity were observed for accession 7271 as 1024 and 236 hemagglutination unit (HAU), respectively. The selected accessions’ relative affinity and HA capability were evaluated using blood from four different sources: human, broiler chicken, local rabbit, and Californian-breed rabbit. The highest HA activity was observed with Californian-breed rabbit RBCs. The lectin assay was stable for about 1–2 h. After the required investigations, the accessions with higher lectin concentration and HA capability could be used as a readily available source of lectins for further characterization and utilization in crop improvement programs.
A Keiki is the product of asexual propagation which naturally develop at the node of a flower stalk or cane. Phalaenopsis produce Keiki along the middle to end nodes on the flower stalk. Although keikis are an inefficient way to propagate orchids on a commercial scale, it is interesting to study the cytokinin hormone Benzyl Aminopurine (BAP) effect to stimulate keikis on a node along the flower stalk. Two nodes of each flower stalk were used in this experiment. Cytokinin hormone (0 mg L−1 , 2 000 mg L−1 , 4 000 mg L−1 , 6 000 mg L−1 BAP) was only applied once to the second, third, fourth, and fifth nodes of the flower stalk base. The Keiki raised from the second and third nodes of the flower stalk while the flower spike raised from the fourth to sixth basal. BAP stimulated bud break on the node of the flower stalk and could produce either flower spike or keikis depending on node position from the basal node of the flower stalk.