Category: plant physiology

Anatomy And Physiology Quiz

Extensive Questions Q.1. Describe the role of auxins in various                         developmental phenomenon in plants? Q.2. Write a note on gibberellins? Q.3. Write a note on application of plant growth                hormones in agriculture? Q.4. (I) Classify plant [Continue]

Plant Tissue Culture Applications

Applications of Plant Tissue Culture Application in Research Work Tissue culture techniques have helped in research work variously: By culturing different tissues on artificial media, knowledge about requirements of various chemical substances (minerals) necessary for the growth of those tissues is found. Organogenesis has been studied by inducing formation of roots, shoot tips, etc. From [Continue]

Abscisic Acid- ABA

Abscissic Acid (ABA) Abscissic acid (ABA) is a ubiquitous plant hormone that inhibits growth of vascular plants. It has been detected in mosses but appears to be absent in liverworts. Several fungal genera make abscissic acid as a secondary metabolite. In algae and liverworts, a compound similar to abscissic acid called lunularic acid appears to [Continue]


A Volatile Growth Inhibitor Ethylene, a growth inhibitor, is the simplest known olefin. It is lighter than air under physiological conditions. It is flammable and readily undergoes oxidation to ethylene oxide, and can be hydrolyzed to ethylene glycol. In most plant tissues ethylene can be completely oxidized to CO2. Ethylene is released easily from the [Continue]


Cytokinins After the discovery of auxins and gibberellins and their influence on growth and development, efforts were diverted to find the factors that would stimulate plant cells to divide. These efforts led to the discovery of cytokinins, they were found to effect other physiological and developmental processes as well. Kinetin Folke Skoog tested many substances [Continue]


For many years after the discovery of auxin, plant scientists attributed all the development and plant processes taking place in plants to auxin. In 1950s another groups of growth substances, the gibberellins, was discovered. The main effect of the hormone was tallness in plants and chemically it was recognized as gibberellic acid (GA). Later many [Continue]


The First Plant Hormone Auxin is the first plant hormone to be discovered and probably the best known of all plant hormones. It plays a major role in the regulation of plant cell elongation and in the growth responses of plants to unidirectional stimuli, known as tropism. Discovery Discovery of auxin is attributed to Charles [Continue]

Plant Growth

 Growth Regulators Growth can be defined as an irreversible increase in dry mass of living material. It actually reflects an increase in amount of protein which has been synthesized, therefore the process of protein synthesis forms the basis of growth. Starting with an individual cell, growth of a multicellular organisms can be divided into three [Continue]


Discovery of Phytochrome Phytochrome is a blue-green pigment involved in the perception of photoperiodic stimuli controlling flowering and other growth phenomenon such as seed germination, etc. The discovery of phytochrome was made during studies by Borthwick, Hendricks and their colleagues. They revealed that a pigment system is involved in the germination of lettuce (Lactuca sativa) [Continue]

Photoperiodic Cycles

Photoperiodic Induction If a plant is exposed to periods of light and darkness long enough to promote flowering, it is said to be photoperiodically induced, and the minimum duration of light needed to initiate floral primordia is called inductive cycle photoperiod. It was observed that if a short-day plant growing under long-short conditions is temporarily [Continue]