Effect of Gibberellic Acid and Some Phenols on Flowering of Impatiens balsamina, a Qualitative Short-day Plant

GA₃ as well as SA (salicylic acid) and β-N (β-naphthol) induce floral buds in Impatiens balsamina under strictly non-inductive photoperiods. The floral bud initiation is accelerated when 1 mg/1 SA is used in combination with 100 mg/1 GA₃. 100 mg/1 GA₃+ 1 mg/1 SA and 100 mg/1 GA₃+ 100 mg/1 β-N increase the number of floral buds as compared with 100 mg/1 GA₃ alone.     

Novel mutations in the transmembrane natriuretic peptide receptor <Emphasis Type="Italic">NPR-B</Emphasis> gene in four Indian families with acromesomelic dysplasia,type Maroteaux

Acromesomelic dysplasia, type Maroteaux is a disorder characterized by disproportionate short stature predominantly affecting the middle and distal segments of the upper and lower limbs. It is an autosomal recessive disorder due to mutation in NPR2 gene which impairs skeletal growth. To screen the mutations in the gene NPR2, all of its coding exons and splice junction sites were PCR amplified from genomic DNA of affected individuals of four families and sequenced. Four homozygous mutations in four different families were identified. These include three novel mutations including a deletion frameshift mutation (p.Cys586Ter), one nonsense mutation (p.Arg479Ter), one missense mutation (p.Val187Asp) and one reported missense mutation (p.Tyr338Cys). The study describes phenotypes of Indian patients and expands the mutation spectrum of the disorder.     

The Theory of Diffusion of Solutes in Pollen; Theory, Design and Experimental Procedure

The theory of diffusion of solutes in pollen is developed andused to derive formulae from which the mean diffusion coefficient() can be determined. A mathematical relation ß_PGC t = ln (C₀/C_f) is developedby employing Fick's law. In this relation is the average diffusion coefficient, ß_PGC is a constantcharacteristic of the pollen, the ‘Pollen Grain Constant’,C₀ and C_f are the initial and final concentration differencesbetween the solution of the solute and the pollen grain andt is the time of diffusion in seconds. A diffusion apparatushas been designed and made. The design is simple to operateand an experimental procedure is described to determine theß_PGC using dilute potassium chloride solutions. Knowingthe pollen grain constant, the method to determine diffusioncoefficient () with any other solute is explained. Diffusion, design, pollen, solutes, theory     

The roles of plant phenolics in defence and communication during Agrobacterium and Rhizobium infection

Phenolics are aromatic benzene ring compounds with one or more hydroxyl groups produced by plants mainly for protection against stress. The functions of phenolic compounds in plant physiology and interactions with biotic and abiotic environments are difficult to overestimate. Phenolics play important roles in plant development, particularly in lignin and pigment biosynthesis. They also provide structural integrity and scaffolding support to plants. Importantly, phenolic phytoalexins, secreted by wounded or otherwise perturbed plants, repel or kill many microorganisms, and some pathogens can counteract or nullify these defences or even subvert them to their own advantage. In this review, we discuss the roles of phenolics in the interactions of plants with Agrobacterium and Rhizobium.     

Effect of Gibberellic Acid and Monophenols on Flowering of lmpatiens balsamina in Relation to the Number of Inductive and Non-inductive Photoperiodic Cycles

A single treatment of plants with GA₃ (gibberellic acid) is not adequate to cause induction under LD (long day: 24-h photo-period) condition, but its effect is added to the sub-threshold induction caused by one SD (short day: 8-h photoperiod) cycle. Floral bud initiation is hastened, and the number of floral buds and flowers per flowering plant increases in plants receiving a single treatment with the combination GA₃+ SA (salicylic acid) accompanying a single SD cycle. However, the increase on 10 replicate basis is more marked in plants receiving three treatments with the combination GA₃+β-N (β-naphthol) and five treatments with the combination GA₃+ SA accompanying six and 10 SD cycles, respectively. The number of floral buds and flowers decreases with an increase hi the number of SD cycles, but it is higher in plants treated with GA₃, SA or GA₃+β-N than in the water-treated controls. — Under long days, treatment of plants with the combinations GA₃+ SA or GA₃+β-N accelerates the initiation as well as increases the number of floral buds. While a minimum of five treatments with GA₃ or of 25 with SA or β-N alone is needed for floral bud initiation under a 24-h photoperiod, three treatments are adequate to induce floral buds with the combination GA₃+ SA or GA₃+β-N under continuous illumination. Ten or more treatments with these combinations under a 24-h photoperiod produce more flowers than the same treatments under an 8-h photoperiod.