Applications of Plant Tissue Culture Group Members Safina

Applications of Plant Tissue Culture

Group Members Safina Aftab Amal Awais Bakhtawar Ali Hina Saif

What Is Tissue Culture? Tissue culture is a process that involves exposing plant tissue to a specific regimen of nutrients, hormones, and light under sterile, in vitro conditions to produce many new plants, each a clone of the original mother plant, over a very short period of time

Importance of Tissue Culture • Produce many copies of the same plant with better physiological and biological outcomes • Produce plants throughout the year regardless of their seasonal value • Eliminate diseases and infections • Useful for preventing starvation in third world countries • Useful for studying GM organisms

Morphological Aspects Understand the factors responsible for cell differentiation and organ formation Cell Dedifferentiation Two Steps of Dedifferentiation: 1) Regression to the cambial stage 2) Return to the cytological structure of primary meristamatic cells

Cell Cultures Provide valuable information on morphogenesis and plant development Cell cultures have contributed to an in-depth understanding of: 1) Cyto differentiation 2) Organogenesis (the most popular theory was hormonal control) 3) Somatic embryogenesis (bipolar embryos “embroids”)

Synthetic Seeds: Artificial encapsulation of somatic embryo, shoot buds or aggregates of cell or any tissues which has the ability to form a plant in invitro or ex vivo condition

1. Micropropagation • Four million genetically identical plants obtained from a single bud • In vitro propagation is based on the proliferation and growth of numerous axillary buds which normally remain dormant in the presence of terminal bud due to apical dominance

2. Production of Secondary Metabolites • Secondary Metabolites are organic compounds that aid in the growth of the plants, but are not required for the plant to survive • Tissue Culture can be used to quickly grow these compounds that have obvious benefits • Shikonin: Component of a Chinese herb. It targets the mitochondria and triggers apoptosis in cancerous cells. It also has the ability to suppress the Human Immunodeficiency Virus (HIV)

2. Production of Secondary Metabolites • Berberine: A compound found in various herbs. It was used in China for thousands of years as an antibiotic and antifungal. It is also used to treat burns and prevent bacterial infection • Ginseng Saponins: Compounds used to treat Osteoporosis and Arthritis. They are also anti-cancer and anti-oxidants

3. Production of Pathogen-Free Plants • Meristem Tip Culture is used, in which the apex is removed from a donor plant and put in an In Vitro Culture. This removes the chances of bacterial contamination. • This culture is coupled with thermotherapy or chemotherapy for complete virus eradication

Production of Pathogen-Free Plants

4. Germplasm Conservation • Germplasm is the entire genetic set of a plant • Germplasm Conservation means preserving this genetic set. It can be in the form of seeds or roots/shoots, but also as a tissue culture. It ha various kinds: • Cryopreservation: freezing of culture, stops growth • Slow Growth Culture: limiting growth

5. Genetic Manipulations Genetic Variability • A measure of the tendency of individual genotypes in a population to vary from one another • Variability of a trait describes how much that trait tends to vary in response to environmental and genetic influences • Genetic variability in a population is important for biodiversity, because without variability, it becomes difficult for a population to adapt to environmental changes, making it more prone to extinction • Through Tissue Culture, the genome of a plant can be modified to get desired traits, such as resistance to pests and diseases

6. In Vitro Pollination • Test-tube Fertilization: Development of seed through in vitro pollination of exposed ovules • In Vitro Pollination: The process of seed formation following stigmatic pollination of cultured whole pistils • Considering the fact that male gametes in plants do not float freely and are delivered by pollen tube, a general term ‘in vitro pollination has been used for ovular pollination, ovarian pollination, placental pollination and stigmatic pollination under in vitro conditions. • In vitro pollination, coupled with embryo rescue, can be useful in overcoming incompatibility barriers between two species in order to get the desired hybrid

The germination of A. frutescens pollen on the C. morifolium stigma imaged at (A) 6 h, (B) 12 h, (C) 24 h, (D) 36 h, and (E) 48 h post pollination. (F) ovules, (G) formation of callus, (H) formation of plantlets.

7. Induction of Haploidy • A recent advance in plant tissue culture and experimental embryology is the successful induction of haploid plants by the culture of unpollinated ovaries or ovules • This means that not only the microspore, but also the megaspore or female gametophyte of angiosperms can be triggered in vitro to sporophytic development, thus opening a new way to genetic research and haploid breeding • Haploid plants are of great use in the study of genes – they allow geneticists to examine genes in hemizygous conditions, and study mutations and pairing • Useful for improvement of crops by shortening the breeding cycles and the production of genetic translocation

8. Somatic Hybridization • Somatic cell fusion is useful in the study of cytoplasmic genes and their activities - this information can be applied in plant breeding experiments • Somatic fusion, also called protoplast fusion, is a type of genetic modification in plants by which two distinct species of plants are fused together to form a new hybrid plant with the characteristics of both – a somatic hybrid

Possible Result of Fusion of Two Genetically Different Protoplasts = chloroplast = mitochondria Fusion = nucleus heterokaryon cybrid hybrid cybrid

9. Genetic Transformation • Genetic transformation is the most recent aspect of plant cell and tissue culture - it provides the means for transferring genes with a desirable trait into host plants and recovery of transgenic plants • Transformation is the step in the genetic engineering process where a new gene (transgene) is inserted into a single plant cell

Production of Transgenic Plants

Tearless Onion Dr Colin Eady (of Crop & Food Research in New Zealand) and his collaborators in Japan have created a tearless onion

Orange, Purple & Green Cauliflowers Orange, purple and green cauliflowers have been created that scientists claim could be healthier for you

Purple Tomatoes High in Anthocyanin Rich in antioxidant pigment Anthocyanin to combat neurodegenerative diseases, depression, and anxiety – maybe even prevent cancer

Conclusion • Plant tissue culture offers many advantages over the traditional methods of propagation • It provides a way to fulfill the ever increasing global demand for food resources • It helps in the conservation of endangered plant species, while allowing us to make completely new and beneficial species

Questions 1. 2. 3. 4. State any one advantage of Tissue Culture. State the two steps of Cell Dedifferentiation. What is Meristem Tip Culture? Why is Genetic Variability important in a population? 5. What is Genetic Transformation? Name one plant that has been genetically transformed.