Plant Biotechnology

Auxin is the primary plant hormone responsible for root initiation and development, particularly adventitious root formation. While cytokinins promote shoot growth, a high ratio of auxin to cytokinin stimulates root differentiation.

Seeds serve as a primary means of preserving plant genetic resources. Therefore, they are stored in seed banks, which are specialized types of gene banks or germplasm banks designed to preserve genetic diversity.

Germplasm refers to the living genetic resources, such as pollen, seeds, or tissue, that are kept for the purpose of animal and plant breeding, preservation, and other research uses. Thus, it represents both preserved genes and preserved cells.

The nitrogenase enzyme complex is composed of two proteins: the Fe protein (a homodimer with 2 subunits) and the MoFe protein (a heterotetramer with 4 subunits). Together, they form a functional complex consisting of 6 subunits.

Proteomics is the large-scale study of proteomes, which are the entire sets of proteins produced or modified by an organism. This field includes the study of protein structures, functions, and interactions.

A research paper that presents original empirical findings, experiments, or direct observations is considered a primary source of data. Secondary sources analyze, interpret, or summarize primary data.

Leghemoglobin is a nitrogen- or oxygen-carrier hemoprotein found in the nitrogen-fixing root nodules of leguminous plants. It regulates oxygen concentration to protect the oxygen-sensitive nitrogenase enzyme.

Rhizobium is a soil-dwelling bacterium that establishes a symbiotic relationship with dicotyledonous plants (specifically legumes) to perform biological nitrogen fixation. Thus, all the options describe aspects of its habitat, host, and function.

The biological or chemical process of converting atmospheric nitrogen (N2) into ammonia (NH3) is known as nitrogen fixation. This process is carried out by specialized diazotrophic microorganisms.

Organogenesis in plant tissue culture is the process of initiation and development of plant organs (such as shoots, roots, leaves, and flowers) from cultured cells or tissues. Thus, it leads to the formation of all plant parts.

Haploid plants are typically produced through anther or pollen culture, a process known as androgenesis. The microspores (pollen grains) inside the anther are haploid, and culturing them allows for the regeneration of haploid plants. Other structures like the embryo or callus are usually diploid unless derived from haploid tissues.

An explant is any plant part, tissue, or organ excised from a donor plant and used to initiate an in vitro plant tissue culture. Other terms like stock and scion refer to parts used in traditional grafting, not tissue culture.

Cybrids, or cytoplasmic hybrids, are produced by the fusion of the cytoplasm of two different cells, resulting in a cell that contains the nuclear genome of one parent but the mitochondrial or chloroplast genomes of both. This is distinct from somatic hybrids, which involve the fusion of both nuclei and cytoplasms.

Polyethylene glycol (PEG) is the most widely used chemical fusogen to induce protoplast fusion in plant biotechnology. It alters the membrane properties, allowing adjacent protoplasts to adhere and fuse. Mannitol and sorbitol are typically used as osmotic stabilizers rather than fusogens.

Dimethyl sulfoxide (DMSO) is a widely used cryoprotectant in cryopreservation. It prevents the formation of ice crystals that can damage cell membranes and intracellular structures during freezing.

Auxins and cytokinins are the two primary classes of plant hormones used in tissue culture. Their relative ratio determines whether cells form a disorganized mass (callus), roots, or shoots.

Gottlieb Haberlandt is widely regarded as the father of plant tissue culture. In 1902, he first proposed the concept of totipotency and attempted to culture isolated plant cells in vitro.