Forest Biotechnology Exam Q&A PDF

Summary

This document appears to be a collection of questions and answers about forest biotechnology. It covers topics such as the aims of forest biotechnology, the meaning of biotechnology, and model plants for tree biotechnology. Various subtopics like domestication processes and micropropagation techniques are also discussed.

Full Transcript

1. What are the main aims of Forest Biotechnology? Could you explain in what branches of biotechnology we can insert forest biotechnology? The main aims of biotechnology goes beyond industrial growth since it provides opportunities for progress towards many of the unsostainable development g...

1. What are the main aims of Forest Biotechnology? Could you explain in what branches of biotechnology we can insert forest biotechnology? The main aims of biotechnology goes beyond industrial growth since it provides opportunities for progress towards many of the unsostainable development goals being part of a bioeconomy sistem. The forest field is about recovering and mainteining natural resourches, improvment of ecosystem services, applying new technologies to use in a more efficient and sustainable way trees species, part of them (cells, tissues, organs) or product of them (primary or secondary metabolites). Beetween the different branches of Biotechnology Forest Biotechnologies can be insert in Green Biotechnologies (application in agricolture and forest), White Biotechnologies (producing energy from biomasess to reduce the use of petrolium, producing paper from woods and biodegradable plastic), Grey Biotechnologies (amelioration od natural environment), Red Biotechnology (for the application in medical and farmaceutical field, an example is the production of diterpene taxol) 2. Can you explain the meaning of the word “biotechnology” and the differences between conventional and modern biotechnology? Biotechnology is the application of science and engeneering in the direct or indirect use of living organism, part of them or product of them in their natural or modified form. This term include traditional biotechnologies and modern biotechnologies. While traditional biotechnologies are used by humanity since thousands of years for example in the fermentation processes in food making, in conventiona breeding, etc…, the term “modern biotechnology”is used to distinguish newer applications such us genetic engeneering, cells fusion, in vitro cultures, etc…. The birth of modern biotechnology is in 1973 when Boyer and Cohen created the first recombinant DNA organism. 3. What are the model plants for tree biotechnology? Why? The main characteristic of a model plants are the small genome size, the fast life cycle, an easy trasformability and a wide distribution, that’s why Arabidopsis taliana is the perfect model for herbacious plants. In trees the genomes are larger, the life cycle is never short, so things changes and the most idoneous species are Populus and Salix, characterized by small genomes (450-550 Mbp). 4. What are the main disadvantages of Arabidopsis as model plant for biotech trees? The main limits of Arabidopsis as a model tree are the facts that has no secondary wood production, it’s no a long living organism, doesn’t have a dormency period and has a less crown complexity. 5. Why could domestication process of tree species be so important for bioeconomy? Bioeconomy means using renewable bioresourches from land and sea to product food, materials and Energy, so the domestication process of trees can play a foundamental role increasing the production of wood and derivates, mitigation of climate change, recovery ecosystem services with a reduced pressure on natural forest and also allows the possibilità to study the species and develope knoledges about their genetics, etology, pedoclimatic esigency. 6. Please, describe the main steps of domestication process? Domestication of agroforesty trees is an accelerated and human induced evolution to bring species into wilder cultivation trought a driven or market led process, The main steps are: -exploration and collection -Evaluation -Tree breeding -Propagation tecnhique -Germoplasm modification -germoplasm distribution -Utilization and marketing 7. Why tree cloning could be useful in a conservation project? Tree cloning is very useful in a conservation process because it’s a way to multiplicate an organism without changing is DNA, so it’s possibile to preserve the genetic in in situ and ex situ collections. 8. Describe the different steps of the protocol for micropropagation by axillary budding. The steps of the protocol for micropropagation by axillary buddings includes the following stages: -Stage 0 (preliminary): selection of a mother donor plant, selection of the explant. -Stage I: culture initiation and establishment: after a 20 minute wash of the explant under running water, sterilization in 1-2% Sodium hypoclorite or 0.1% of mercuric chloride and another wash in distilled water to remove the surface of sterilizant the explant iso put in the medium and callogenesis occurs -Stage 3:Shoot moltiplication: in this phase the ratio AUXs/CKs ha sto be in favour of Citokinins. Sometimes can be useful to add Auxins that can help shoot’s development, but in some species only. 9. Describe the different steps of the protocol for micropropagation by adventitious budding. In replication from adventiscious buddings new buds form from non-meristematic tissue (such as the internodes, leaf bases, or even root tissue), without any pre-existing meristem. This process requires the initiation of meristematic activity in cells that normally do not produce buds, often achieved with a higher concentration of growth regulators, particularly auxins. 1.Selection of Explants: Non-meristematic tissue (like leaves or internodes) is chosen. 2. Washing and Sterilization: The explant is sterilized similarly to prevent contamination. 3. Induction of Buds: Higher concentrations of auxins and cytokinins are applied to induce meristematic activity in non-meristematic cells, which then form adventitious buds. 4.Shoot Development: Once buds are formed, they are transferred to a medium that supports shoot elongation. 5.Rooting and Acclimatization: Like axillary budding, shoots are then rooted and acclimatized for planting. In summary, axillary budding is a more stable and predictable method, while adventitious budding can offer higher multiplication rates but with a slightly higher risk of genetic variability. 10. Why is it necessary to acclimatize in vitro plants before planting and how do it? It’s necessary to acclimatize in vitro plants because they takes sugar from the medium and not from a photosyntethic process, so they need to adapt from heterotrofy to autotrofyy but also because they need time to adapt from the in vitro medium to the soil, It requieres a 2-4 weeks time progressivly reducing humidity and increasing light intensity in green house. 11. What are the other factors together with the genotype, which can affect the success of an in vitro culture? Such factores are the explant sterilization, medium components used, phyotormones and sugar source, illumination, humidity, tipe of tissue sourche 12. How does a vitrified plant look like? What does vitrification depend on? Can you recover vitrified plants? A vitrified plants is caracterized by a visible glassness and traslucency and it depends from an hyperghydricity condition. Hyperhydricity generates a kot of losses in in vitro cultivation because it’s more impossibile than difficult to recover a plant in hyperdricity condition. It’s better to prevent the situation. 13. Phenolic exudation can be toxic for in vitro material. Please, describe when it normally takes place and how you can prevent it. Phenolic exudation takes place when explant is cutted from the plant and placed into new environt or culture. In the early step of the process explant will be under stress and it release a lot of phenolic compounds, these compounds prevent plant tissue to be in a good micropropagation or even it may occus necrosis. To avoid this condition there are some tips might be useful 1.Using antioxidants – acorbic acid, citric acid to the culture medium prevent from toxicity 2. Subculturing frequently – transferring transplants into new culture media helps to avoid phenolic compounds 3. Ligh intensity and controlled temperature – low light intensity and being in an optimal temperature can help explant to aid phenolic exudatives 14. Describe the different steps of the protocol for somatic embryogenesis. The steps of micropropagation by somatic emryogenesis are 1, Initiation in vitro after the selection of the explant and the sterilization to obtain embryogenetuc culture 2.If there isn’t a conservation of the germoplasm by cryopreservation it goes to the moltiplication stage with a proliferation of the culture 3. Maturation phase to obtain cotiledonary Somatic Embryo 4.Dessication phase: obtaining dessicated somatic embryo 5. Germination 6. Acclimatization in green house 7. Tree culture 15. Please describe the difference between somatic and zygotic embryos. A zygotic embryo can be obtained by gametic reproductionso it results by the fusion of the paternal and maternal character (n+n). A somatic embryo i san embryo obtained by a somatic cell so it has the same DNA of the organismo of the explant. 16. What is an embling? A plant derivated from Somatic Embryogenesis is defined a san embling. 17. What is the difference between direct and indirect micropropagation? In the indirect micropropagation there is the intermediate step of callogenesis befor the formation of new non-meristematic tissues, It is useful when we do not have a chance to get shoots or roots from the explant directly that explant is not ready for making shoot or root without making callus. But in indirect micropropagation the Callogenesis step is skipper.Within this reason this micropropagation might be useful in timing since we get result faster, reduces chance of somaclonal variation, 18. Why can some rhizobacteria (PGPR) have beneficial effects on in vitro plants? PGPR can have beneficial effects to in vitro plants leading them to: -be more vigorous organisms in the field -have better rooting in recalcitrant species -reduce the need of chimica fertilization - Anhancing acclimatization - Disease prevention or biologic control – rhizobacterais can help in vitro plant to avoid any microbial disease while producing antimicrobial compounds 19. Are there other microorganisms beyond rhizobacteria considered Plant Growth Promoting Microorganisms? Beyond the rhizobacteria there are other types of microorganisms that helps plant growth 1.Endophytic fungi – fungus that live in plant tissue and they increase the nutrient uptake, growth hormone resistant to environmental stresses 2.Nitrogen -fixing bacteria – increase nitrogen availability, especially for plants which live in a limited source of nitrogen 3. Plant-growth promoting yeast - offer growth promotion and biocontrol from harmful fungi 4. Mychorizzal fungi 20. What kind of tree species is normally produced by using somatic embryogenesis? Have you an idea on the potentiality of this method? The first woody angiosperm replicated with S.E. was Santalum album in the1960s. Currently a wide range of woody angiosperms can be replicated using S.E, For example: pinus, populus, eucalyptus, some citrus species and some tropical trees 21. What is a synthetic seed? A synthetic seed i san incapsulated propagation material (can be S.E., shoot buds, callus agreggate) that also has supplementary nutrition material and not just protection. 22. What is haploid technology? The aploid technology allows to produce aploide plants which have only one set of chromosomes. It consist to develope a complete plant starting from pre-gametic cells stopping their development into a mature gametic cell with antimitotic agents to somministrate during metaphase or anaphase. In the case of androgenesis the microspore get isolated, threathed before they become pollen and then cultivated to be an aploide plant. Haploids are more sensitive to disease and they’re a not fertile, therefore doubling the chromosomes is required in order to obtain fertile plants. The result will be double haploids, also called homozygous diploids and this production allows a single step development skippinbg different backcrosses that are required in conventional breeding. Considering he long ontogenic cycle of the trees this could be very useful. 23. What is the main advantage for doubled haploid plants in trees? Double haploids allows a single step development skippinbg different backcrosses that are required in conventional breeding. Considering he long ontogenic cycle of the trees this could be very useful. 24. What kind of in vitro protocol should be adopted if we want to maintain genetic fidelity with respect to the mother plant? To maintain genetic fidelity in an in vitro protocol:  Use axillary bud or meristem culture to avoid genetic changes.  Avoid callus formation by promoting direct organogenesis.  Minimize the number of subcultures.  Carefully control growth conditions and hormone ratios.  Use genetic markers to test for genetic stability. 25. Please, describe some in vitro protocols you can use to increase the genetic variability of a species. The somaclonal variation is the genetic variability generated by the use of a tissue culture cycle characterized by different steps, starting from protoplast culture, cell suspension culture or callus culture. -Induced Mutagenesis: Chemical or radiation-induced mutations. -Somaclonal Variation: Using callus culture to encourage natural variation. -Protoplast Fusion: Fusion of cells from different species or varieties to create hybrids. -Polyploidy Induction: Increasing chromosome number for desirable traits. -Genetic Transformation: Introducing new genes using Agrobacterium or gene guns. -In Vitro Selection for Stress Tolerance: Applying stressors to select for resistant variants. -Embryo Rescue and Wide Hybridization: Culturing hybrid embryos in vitro. 26. Please, describe the history of Taxol as secondary metabolites obtained by in vitro procedures. The diterpen taxol was discovered in the 1960sand it’s a secondary metabolita from Taxus brevifolia. It has a big medical importance recognized by the US National Cancer Institute, but the demand was 300kg/year, that corrisponds to 750000 trees, to much considering that when the chemioterapic proprieties of the substance was discovered the species was risking to diseappear. In 1992 the taxol production was made with plant’s cell culture In 2002 plant cell suspension culture wasintegrated with the use of some elicitors In 2005 five the production was of 2,71 mg/L In 2007 was obtained a semi synthetic taxane 27. Please describe the main biotech material you can obtain starting from a callus culture. They’re somatic embryos, synthetic seeds, micropropagated organism, metabolites, new varieties,recombinant proteins 28. Please describe exactly the meaning of the word “regeneration from a callus”. Callus in tissue culture is defined a san unorganized meristematic tissue mass growing. Regenaration from callus means to create an organogenesis or somatic embryogenesis means to create an organogenesis or a somatic embryogenesis starting after callogenesis. 29. What is a somaclonal variation? The somaclonal variation is the geneetic vatiability generated by the use of a tissue culture cycle chracterized by different steps 30. Please describe why the production of secondary metabolites by using cell culture system could be more convenient to respect the extraction from fresh plant tissues. The production of secondary metabolites is more convenient by cells culture because it allows a more mirate e larger production (able to satisfy industrial requests) avoiding the depauperation of natural resourches like organisms, sometimes of endangered species, and others (like soil for example) This also avoid the artificial selection to improve the expression of genes of interests for the production of the metabolite and sometimes, like in the case of the taxol as a chemiotherapic substance makes a large production possible. It also requires a much shorter time in particolar with tree species.

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