Journal of Plant Molecular Breeding
Volume:1 Issue: 1, Summer and Autumn 2012

World population has already exceeded 6.5 billion, out of which about 850 million (13 percent) are undernourished. With the current growth rate, the world community faces even a greater challenge of hunger and food security as the estimated the population will catch 9 billion by the year 2050 with doubled needs for food. At the same time, preservation of biodiversity, stopping deforestation and reduced environmental footprint caused by agricultural practice are the main concerns towards sustainable agriculture. The progressive adoption of genetically modified organisms (GMOs) including GM crops and trees can make a decisive contribution to improve harvest and alleviate hunger and poverty. In addition to the environmental benefits, the introduced GMOs can improve water use efficiency and reduce the need for fossil based fuels and pesticide application and reduce thousands of tons of emissions of green house gases. In this respect, several social issues are still of concern. On one hand, many beneficial advantages of GMOs have encouraged a wide spectrum of large or small farmers to cultivate transgenic plants which is translated to food security and job opportunities. On the other hand, while ideological debates have hindered, or even ceased, technology provisions in developing and underdeveloped countries, GMO seed and food productions are monopolized by a quite small number of transnational companies. For instance, seeds that were previously available at low or no cost, mainly through public institutes, international entities or seed exchange among farmers, would be offered at higher prices due to exclusive right of producers and additional cost of patent royalties. Cartagena protocol is going to regulate the relationship among countries aiming at preservation of world biodiversity. Although the developing countries outnumbered developed nations that cultivate transgenic plants in recent years, current statistic shows that around 84 percent of GMO crops are cultivated by only four countries, USA, Brazil, Argentina and Canada. Scientist and scholars, particularly in Islamic states, as well as decision makers are the major responsible bodies that must take roles for the current and future situations. Despite the fact that most of scientists or scholars are not in navigation positions, however, they can discuss socio-economic issues and raise public awareness in order to harmonize their efforts towards proper utilization of biotech products in their society and towards a reliable point for food security and safety.

Gamma irradiation was used at different doses (80, 160 and 240 Gy) on Glycine Max (L.) Merrill cv. Hill homogenous seeds. A single suitable M2 plant was selected and evaluated at M3 and M4 along with its parent and three other varieties as control in RCBD experiment in Sari Agricultural Sciences and Natural Resources University’s experimental field. M-80-709 and M-160-3429 mutant lines were significantly shorter (55.05 and 72.04 cm respectively). Their branch numbers were however significantly more (8.70 and 11.53 respectively) compared to the parent cultivar (80.82 cm and 6.10 respectively) and other genotypes (p≤0.05), when calculated on per plant basis. Besides, the M-160-3429 was characterized by highest grain yield and oil content (38.25 g and 19.22% respectively), in compare with its parent (12.73 g and 19.09% respectively) and all others control cultivars (p≤0.05). The M-160-3429 mutant line with high grain yield and oil content accompanied with some other favorite morphological traits can be considered as a new promising line of soybean for future studies. Results from this study suggested that mutation breeding procedures at the ranges of 80 to 160 Gy is a capable me­thod for breeding higher grain yield including increasing the oil content as well.

DNA methylation as an epigenetic mediator plays the important role in spatial and temporal gene regulation and ensures the stability and the plasticity of organism. In this investigation, methylation sensitive amplification polymorphism (MSAP) were assessed in CCGG sites on a halophytic plant, Aeluropuslittoralis in response to different temperature stresses including freezing, low and high temperatures. A combination of 13 primers were able to produce 500 bands, of which 74%, 20.8% and 5.2% were of type I (non methylated fragments), type II (CpG methylated fragments) and type III (CpCpG methylated fragments), respectively. Among these bands, 130 bands were methylated fragments with the highest occurrence of methylation at CpG internal cytosine. The results showed that up to 2% of all methylated bands were polymorphic, which belonged to types II and III. Highest levels of methylation alternations were detected under high and freezing temperatures. The results suggest that apart from cis regulatory logic plant response to the environmental temperatures may be regulated by methylation of CCGG sites of stress-related loci.

The hydrophobic proteins of plant plasma membrane still remain largely unknown. For example in the Arabidopsis genome, receptor-like kinases (RLKs) are plasma membrane proteins, functioning as the primary receptors in the signaling of stress conditions, hormones and the presence of pathogens form a diverse family of over 610 genes. A limited number of these proteins have appeard in protein profiles. The detection of these proteins and thus the determination of their dynamics and tissue specificity, is technically challenging due to their low abundance and association to a lipid membrane. To identify new putative membrane proteins especially receptor systems, we used a gel free proteomic strategy based on mass spectrometry analyses of a plasma membrane fraction enriched in hydrophobic proteins. We produced from Arabidopsis leaf a highly purified plasma membrane fraction with the aqueous two-phase partitioning technique. By separating the proteins in the plasma membrane fraction with ion exchange and reverse phase chromatography and analyzing the resulting fractions on a MALDI-TOF mass spectrometer, over 900 proteins were detected. The plasma membrane proteome generated by this approach contains numerous plasma membrane integral proteins, one-third displaying at least four trans-membrane segments. An in silico analysis shows a correlation between the putative functions of the identified proteins and the expected roles for plasma membrane in transport, signaling, cellular traffic and metabolism. Of these proteins, 304 were annotated as membrane proteins, 69 were RLKs, distributed among the different receptor families in proportions reflecting the distribution in the genome. Of the RLKs that were identified, most are reported for the first time at the protein level and will constitute interesting targets for further functional studies.

A significant portion of the world’s cultivated land is affected by salinity that reduces crop productivity in these areas. Breeding for salt tolerance is one of the important strategies to overcome this problem. Recently, genetic engineering is becoming a promising approach to improving salt tolerance. In order to improve the yield performance of canola in saline soils, we transformed canola with Arabidopsis vacuolar Na+/H+ antiporter gene AtNHX1 which enhances the plant capacity for reducing cytosolic Na+ by transporting Na+ into the vacuole. Southern analysis of putative transgenic plants indicated that only one copy of the gene integrated into the plant genome. Overexpression of the AtNHX1 gene was shown in T1 transgenic plants. Under salinity conditions, stem and root length and overall biomass of transgenic plants were significantly higher compared to those of nontransgenic plants. Moreover, salt treated transgenic plants contained high proline and K+, but less Na+ compared to wild type.

Establishment of an efficient and reproducible regeneration protocol is one of the basic prerequisites for genetic transformation of any crop plant. In vitro culture of lentil has proven to be difficult. In spite of a number of reports on the regeneration of this plant, very few satisfying and reproducible protocol has yet been reported. This study carried out for investigation of different hormone treatments and explants in order to establish a reproducible protocol for indirect in vitro regeneration of the cultivar Gachsaran (commonly grown in Iran). For this purpose, the effects of 13 different hormone treatments and 4 explants on callus induction and regeneration were studied. Callus with the highest fresh and dry weight was produced on modified Murashige and Skoog (MS) medium containing 1 mg/L α-naphthaleneacetic acid (NAA)and 1 mg/L Zeatin (medium E). Among the explants, decapitated embryos attached to 1/4 of the cotyledon (DEAC) produced callus with the highest fresh and dry weights. In the regeneration stage, calli induced on media supplemented with 2,4-dichlorophenoxyacetic acid (2,4-D) alone or in combination with other hormones did not result in shooting or rooting responses. The highest shooting and rooting responses (75%) were observed for callus induction medium E, using decapitated embryos with a quarter of the cotyledon as the explant.

Study of genetic relationships is a prerequisite for plant breeding activities as well as for conservation of genetic resources. In the present study, genetic diversity among and within 15 Iranian native Ajowan(Carum copticum L.) populations were determined using inter simple sequence repeat (ISSR) markers. Twelve selected primers produced 153 discernible bands, with 93 (60.78%) being polymorphic, indicating considerable genetic diversity at the population level. Number of polymorphic bands per primer ranged from 4 to 11 with an average of 7.75. The largest percentage of polymorphic loci was 78.57% for primer UBC818. Based on an un-weighted pair-group method using arithmetic average (UPGMA) clustering algorithm, four distinct groups were established. Results of the principal coordinate analysis (PCoA) corresponded to those obtained through cluster analysis. Analysis of molecular variance (AMOVA) showed that the genetic variation was found mainly within populations (61%), but variance among populations was only 39%. This study has detected significant genetic differentiation among C. copticum populations. The current study confirmed the importance of molecular studies in detecting genetic variation among genotypes in selecting diverse parents to carry out crossing program successfully.