Plant Growth and Hormones

Application of GA can induce flowering in long day plants. It has no favourable effect on size of flower and fruit in certain plants. The genetically dwarf plants can be made tall by application of GA.

Crown gall disease involves the transfer of T-DNA into the plant genome, which causes the plant cells to produce auxins and cytokinins, leading to excessive meristematic activity and tumor growth.

Agrobacterium tumefaciens is the causal agent of crown gall disease (the formation of tumours). It is a rod-shaped, Gram-negative soil bacterium. The plasmid of this bacterium is called Ti-plasmid, it shows T-DNA. This plasmid used to produce growth hormones like auxins and cytokinins.

So, the correct option is ‘Growth hormones like auxins and cytokinins’.

 Vernalization is the process of induction of flower by prolonged exposure to cold temperature. It is an adaptation shown by plants which are exposed to harsh winter followed by relatively short growing seasons. Vernalization is practiced artificially too.

In many plants, the temperature has a profound effect on flowering. Some plants do not flower under the inductive photoperiod conditions but flower when a cold temperature treatment is given to them. This acquisition or acceleration of the ability to flower by a chilling treatment is said to be vernalization. It is the method of inducing early flowering in plants by pretreatments of their seeds at a very low temperature. Thus option C is the correct answer. 

Vernalization promotes early flowering in plants that would otherwise require a longer vegetative period, effectively shortening the time spent in the vegetative phase.

When gibberellins were applied to certain cold-requiring plants, they flowered without low-temperature treatment. Thus it is conceivable that gibberellins could induce certain changes within the plant which in turn lead to flowering. Thus option B is the correct answer. 

Vernalization is the acquisition of a plant's ability to flower in the spring by exposure to the prolonged cold of winter, or by an artificial equivalent. It can also refer to herbal plants requiring a cold dormancy to produce new shoots and leaves. The stimulus of vernalization is known as vernalin. The stimulus of vernalization that induce flowering could be a particular gibberellin or a mixture of gibberellins.

Vernalization is the physiological process that allows plants to bypass or compensate for the requirement of a specific temperature phase (thermophase) for flowering.

Vernalization is the process by which plant can be induced to flower by exposing it to the prolonged cold of winter. The term was coined by Lysenko in 1928. He stated that certain plants can be made to flower by providing low temperature treatment to young plants or moistened seeds. Other terms like jarovization, springification were also coined for the same phenomenon. However, today the most accepted term is vernalization.

Vernalization is the process by which plant can be induced to flower by exposing it to the prolonged cold of winter. Plants can be made to flower by providing low temperature treatment to young plants or moistened seeds. Vernalin is a plant hormone that is produced on vernalization. It induces flowering in plants.

Vernalization is the induction of a plant's flowering process by exposure to the prolonged cold of winter, or by an artificial equivalent. After vernalization, plants have acquired the ability to flower, but they may require additional seasonal cues or weeks of growth before they will actually flower. Vernalization is sometimes used to refer to herbal (non-woody) plants requiring a cold dormancy to produce new shoots and leaves but this usage is discouraged. Many plants grown in temperate climates require vernalization and must experience a period of low winter temperature to initiate or accelerate the flowering process. This ensures that reproductive development and seed production occurs in spring and winters, rather than in autumn. The needed cold is often expressed in chill hours. Typical vernalization temperatures are between 5 and 10 degrees Celsius (40 and 50 degrees Fahrenheit).

Vernalization is the process by which plant can be induced to flower by exposing it to the prolonged period of low temperature or cold. After this, plants show quicker flowering. Gibberellic acid is a plant hormone which helps in growth of stem. It also brings about the rapid flowering in plants.

Plant growth regulators also called as phytohormones are the plant hormones that help in the various processes of plant-like flowering, ripening of fruit etc. They are secreted in the root, shoot and include all part of the plant body and any tissue is able to release and any tissue is able to accept them and work accordingly. These are auxin, gibberellin, cytokinesis etc.