Tag Archives: Agriculture

Micropropagation of Capsicum Annuum

Samantha Beck, Utah Valley University

Agriculture

Capsicum annuum (hot chili pepper) originated in Central and South America but due to its many economically important characteristics this species is now used all throughout the world in many varied applications. Encompassing many diverse varieties, each with distinctive beneficial characteristics such as spiciness (pungency), this species has become a focal point for research. The “pungency” is due to its secondary metabolites called Capasaicinoids (Capsaicin and Dihydrocapsaicin among others); making these varieties useful in food products and the pharmaceutical industry. Metabolites from C. annuum have shown to be effective against inflammation, pain, psoriasis, high cholesterol, atherosclerosis and other ailments. Evidence also has shown that these secondary metabolites (Capasaicinoids) trigger cell suicide in prostate cancer cell lines. Micropropagation of this important species is crucial for breeding programs, analysis of secondary metabolites, propagation at industrial level and development of research in different fields. This research evaluates the effects of different plant growth regulators on the embryogenesis and organogenesis of three varieties of pepper: Jalapeno, Cayenne and Thai. Reliable organogenesis and embryogenesis methods in these varieties have not been published. Our results show that callus growth was stimulated in these varieties with MS media amended with 5μM BAP (6-Benzylaminopurine) and 2.5μM 2,4-D (2,4-Dichlorophenoxyacetic). The response to fruit extract on callus growth was evaluated; the Jalapeno variety responded positively to the addition of fruit extract whereas the Thai variety did not show induction of callus. Additional effects of different concentrations of growth regulators and different medium on embryogenesis and organogenesis will be described. This research provides valuable information that can be used by researchers and commercial propagators.

The Induction of Polyploidy in Agastache Plants

Ryan Graham and Bryson Ensign, Brigham Young University

Agriculture

Agastache is an aromatic flowering plant closely related to the mint family. Most species are 0.5-3m tall with toothededged leaves covering the stem. Agastache is commonly found in landscaping, but can become quite noxious because of the abundance of seed produced in each flower head. Here we used an antimitotic agent, trifluralin, to induce polyploidy in Agastache seedlings with the foresight of creating a sterile version of the plant. Putative polyploids were checked for chromosomal content via flow cytometry. Our data show that trifluralin treatment is a potentially successful method for inducing polyploidy in Agastache. Further, among the positively identified polyploids, we have noticed suggestive patterns of sterility. However, further research needs to be conducted to confirm this finding. For now, we are able to present an effective method for inducing polyploidy in Agastache and, potentially, other plant species.

Expression of Cdk5r1, and Not Cdk5, Induces Primary β-cell Pro liferation

Carrie Draney and Amanda Hobson, Brigham Young University

Agriculture

Decreased β-cell mass is a hallmark of type 1 and type 2 diabetes. The use of islet transplantation as a diabetes therapy is hampered by the relative paucity of transplant ready islets. Greater understanding of the proliferative pathways controlling islet proliferation may be harnessed to increase functional β-cell mass through transplantation or by enhanced growth of endogenous β-cells. We have shown that the β-cell transcription factor Nkx6.1 induces β-cell proliferation by upregulating the orphan nuclear hormone receptors Nr4a1 and Nr4a3. Using expression analysis to elucidate the Nkx6.1 independent mechanism by which Nr4a1 and Nr4a3 induce β-cell proliferation, we demonstrated that cyclin-dependent kinase 5 regulatory subunit 1 (Cdk5r1) is upregulated by Nr4a1 and Nr4a3 and not Nkx6.1. Adenovirus mediated overexpression of Cdk5r1 is sufficient to induce proliferation in primary rat islets. The observed proliferation is primarily in β-cells. Glucose stimulated insulin secretion is maintained with Cdk5r1 overexpression. The Cdk5 inhibitor, roscovitine, blocks islet proliferation, suggesting that Nr4a mediated β-cell proliferation is a kinase dependent event. Overexpression of Cdk5r1 results in pRb phosphorylation, which is inhibited by roscovitine treatment. These data demonstrate that activation of the Cdk5 complex is sufficient to induce β-cell proliferation while maintaining glucose stimulated insulin secretion.

Micropropagation studies of Calochortus species

María Velasco, Utah Valley University

Agriculture

Calochortus is a plant genus that includes approximately 60 species distributed in North America with great ornamental and ethnotobanical value. Sego lily, mariposa lily and other common names have been used to describe the different species of Calochortus. Native Americans and settlers have used the bulbs as food, either raw or ground into flour and cooked. C. nuttallii played an important role in the success of colonization of Utah. Between 1840 and 1851 the scarcity of food due to a plague of crickets led to the pioneers to dig for the bulbous roots of sego lily, ensuring the survival of the pioneer population. This research studies the effects of Gibberellic acid on the germination and elongation of these species in vivo and in vitro. Eight different species of Calochortus are being utilized for this experiment to evaluate the effect of this growth regulator on the germination of these species. Different types of media are being tested to evaluate the optimal in vitro conditions that these species require for germination and growth. In addition embryogenesis and organogenesis is being induced by using Benzyl Amino Purine and 2,4-Dichlorophenoxyacetic acid at different concentrations. Sego Lily is the State flower of Utah; micropropagating this plant will allow us to understand and research new methods and conditions to grow these species successfully, making preservation possible since some Calochortus species have been listed as endangered. In addition, other species such as Calohortus ambiguous (Doubting Mariposa Lily), which is distributed in Utah, Arizona and New Mexico, will also benefit from the system developed in this research because they are closely related to Sego Lily (C. nuttallii). The long term goal of this research is to establish an appropriate micropropagation system for a wide variety of Calochortus species.