Sago palm, a monocot, is one of the most important economic species and now grown commercially in Malaysia, Indonesia, Philippines and Papua New Guinea for production of sago starch and / or conversion to animal food or fuel ethanol. In many countries South East Asia, except Irian Jaya, M. sagu is mainly found in semi-cultivated stands. Irian Jaya has about 6 million ha of M. sagu. The stands of good quality M. sagu can be quite large. Papua New Guinea has an estimated 1 million ha of wild and 20 000 ha of semi-cultivated M. sagu. M. sagu is also found in Guam, Palau, Nakuoro, Kosrae, and Jaluit, Marshall Islands most likely the result of human introduction (Mc Clatchey et al. 2006)
Sago palm is a crop that can produce starch in a whole lot from one tree. It is a robust monocotyledon as it can grow in soils where only few plants can survive such as the waterlogged, immature, acidic and deep peat of Sarawak. This swampy peat environment has covered 12% of Sarawak's total land area (Tie and Lim, 1977) and based on this fact, the Sarawak Government has focused their effort to develop the sago industry through the Department of Agriculture (DOA), Sarawak in 1982.
Get your grade
or your money back
using our Essay Writing Service!
As an early result, a commercial sago plantation was developed in Mukah in 1987 by the Sarawak Land Custody and Development authority (LCDA) as well as a Crop Research and Application Unit (CRAUN) in 1993 to undertake more intensive research and development on sago (Jong, 1995). One of the research areas conducted by CRAUN is sago palm tissue culture. Currently CRAUN's tissue culture (TC) laboratory has been developing in vitro propagation system in order to cope with the plantation demands where the clonal has being planted on a large scale.
However the long maturation period, variable starch quality and total lack of selected quality varieties as planting material are the major issues that need to be overcome by genetic improvement of sago palm. In order to improve the existing palm characteristic in a short space of time, genetic transformation holds great potential. Sago palm transformed with new genes that is coding for characters such as high yield, starch quality, early maturity, etc. will be resulting in the production of improved sago palms for commercial planting.
Conventional plant breeding has succeeded in producing a wide variety of commercial plants and crops with a range of important agronomic traits. It has succeeded in converting a Mexican grass into maize and Middle East grass into wheat. However, it is to a large extent a hit-or-miss process, combining large parts of parental genomes in a rather uncontrolled fashion, although this is currently being improved due to the modern technique of marker assisted breeding. Genetic engineering, on the other hand, allows scientists to transfer very specific genes into plants, resulting in the introduction of one or more defined traits into a particular genetic background. This process is called genetic transformation and the genes involved are expressed to form a protein responsible for the particular trait. The traits involved include herbicide and drought tolerance, and resistance to viral, bacterial and fungal pathogens as well as to herbivorous insects. The added advantage is that the transferred gene(s), or transgene(s), can come from any organism as long as its expression is compatible with its new host (Thomson).
Genetics transformation or genetic engineering technologies have been widely used for improvement of monocotyledonous crops such as maize, rice and oil palm. The improvement of the qualities of these crops through genetic engineering has stimulated and indeed often widened their commercialization prospects (Ruslan et al., 1997). Sago palm has one of the important prerequisite in the production of transformed or transgenic plant; and that is the ability of its cells to grow, divide and eventually regenerate into plant in vitro. Usually during its recovery, wounded plants like sago palm form a mass of undifferentiated tissue known as callus. The callus, in turn, can be induced by hormones in vitro to produce shoots in vitro and can also be used as a target for genetic transformation using either the biolistic gun or Agrobacterium-mediated methods.
At present, the most routinely and widely used method to obtain transgenic plants is by the use of Agrobacterium-mediated method. Formerly this method was less successful with monocots but more recently it has been possible to transform monocots using Agrobacterium-mediated method, for crops such as rice, maize, yam and palm oil (Ming Cheng et al., 2004).
Always on Time
Marked to Standard
There is an urgent need to improve the sago palm for plantations through non-conventional methods and it is timely to develop a procedure for genetic improvement of sago palm. However currently there are a few projects, conducted in CRAUN and UNIMAS, looking at isolating the genes involved in various biochemical and physiological processes in sago palm. These genes once isolated and characterized, can then be used to improve the sago palm. Ultimately, palms can be produced with enhanced characteristics such as improved yield and starch quality. Therefore the establishment of a transformation protocol in sago palm is essential in order to re-introduce the altered genes or other novel gene sequences into sago genome.
In this study, bar and gus genes, will be used as marker genes to indicate the success of the transformation system. Two approaches were tested in this research project which are Agrobacterium-mediated and microprojectile bombardment. Although genetic transformation on monocotyledonous plants is usually known to have a low-efficiency (Willmink et al, 1993), both of these methods were proven to have succeeded in maize, wheat, rice and oil palm.
One of the factors that can increase the transformation efficiency is the technique of effective selection. Selection after the transformation is important to inhibit growth of the untransformed cells and to enable transformants to survive and regenerate into complete transgenic plants. Or else, a majority of nontransformants will dominate the culture and producing chimera plants.
In plant genetic engineering, it is important to obtain a plant which holds the transformed genes in the plant genome. Plant like sago that has slow tissue culture and regeneration process therefore a system for efficient selection is important. Poor selection system will allow agents in the non-transformant cells to replicate, especially when the selection agents is less active after a in certain culture incubation period and this will lead to the production of chimeric. (Parveez et al 1996). Basta™ is used as a selection agent for M. sagu because it has been successfully used on the selection of the palm oil transformants. Moreovers the newly planted sago palm in the plantation showed high sensitivity towards Basta ™ during routine application to control the weeds which might be a good indicator for the presence of the new genes.
The efficiencies of the system were proved by DNA analysis. The transformants DNA were extracted and analyzed through gus staining, Basta ™ selection media, PCR, dot blot analysis, RFLP-based DNA mapping and Southern Blot Analysis.
Thus, the objectives of this experiment are to:
develop the sago palm suspension culture system.
identify the parameters needed to genetically transformed sago palm via Agrobacterium tumefaciens and/or particle bombardment
screen for transformed cell lines and generate transgenic sago palm
carry out molecular analysis and characterization of the transgene for stability in transgenic sago palm.