Spatiotemporal oscillations of morphinan alkaloids in opium poppy.

Here, a comprehensive endeavor is made to simultaneously scrutinize spatiotemporal oscillations of three imperative morphinan alkaloids (i.e. thebaine, codeine, and morphine) alongside dynamic transcriptional patterns of TYDC, SalAT, COR, T6ODM, and CODM genes in different tissues of Papaver somniferum (i.e. root, bottom part of stem, upper part of stem, leaf, capsule wall, and capsule content) over five distinguished ontogenic stages (i.e. rosette, bud initiation, pendulous bud, flowering, and lancing). Apart from bottom stem and leaf, the maximum thebaine content occurred in lancing stage, while its minimum content did not follow a systematic rhythm, either among six tissues or five various sampling times. Regarding codeine, excepting upper stem, the highest ratios of codeine were observed at flowering and lacing stages, while negligible amounts were overall detected at early stages of plant growth like rosette. Considering morphine, apart from upper stem, it appears that late ontogeneic times including lancing and flowering are the most appropriate phases to achieve high amounts of morphine, while at early stages the aforesaid alkaloid possessed lower accumulation. Furthermore, all the five genes under study, overall, exhibited a variety of transcript levels either among six tissues or five various sampling times. Interestingly, a connection occurred between transcript ratio of SalAT and thebaine content, suggesting that thebaine biosynthesis is coordinated tightly by the enzymatic function of SalAT enzyme. Meanwhile, despite low magnitudes of T6ODM and CODM transcripts in the root-harvested samples at pendulous bud and flowering stages, both codeine and morphine were surprisingly in acceptable quantities, plausibly owing to the translocation of both alkaloids from the producing (source) tissues to the roots (sink), known as a phenomenon of 'source-to-sink transportation'. The results, altogether, could provide us enough information in acquiring new insights towards potential impacts of spatiotemporal oscillations on the magnitudes of all the above-mentioned alkaloids alongside transcription ratios of the key genes in opium poppy.

The proteome response of salt-resistant and salt-sensitive barley genotypes to long-term salinity stress.

Responses of plants to salinity stress and the development of salt tolerance are extremely complex. Proteomics is a powerful technique to identify proteins associated with a particular environmental or developmental signal. We employed a proteomic approach to further understand the mechanism of plant responses to salinity in a salt-tolerant (Afzal) and a salt-sensitive (Line 527) genotype of barley. At the 4-leaf stage, plants were exposed to 0 (control) or 300 mM NaCl. Salt treatment was maintained for 3 weeks. Total proteins of leaf 4 were extracted and separated by two-dimensional gel electrophoresis. More than 500 protein spots were reproducibly detected. Of these, 44 spots showed significant changes to salt treatment compared to the control: 43 spots were upregulated and 1 spot was downregulated. Using MALDI-TOF-TOF MS, we identified 44 cellular proteins have been identified, which represented 18 different proteins and were classified into seven categories and a group with unknown biological function. These proteins were involved in various many cellular functions. Up regulation of proteins which involved in reactive oxygen species scavenging, signal transduction, protein processing and cell wall may increase plant adaptation to salt stress. The upregulation of the three of four antioxidant proteins (thioredoxin, methionine sulfoxide reductase and dehydroascorbate reductase) in susceptible genotype Line 527 suggesting a different tolerance mechanism (such as tissue tolerance) to tolerate a salinity condition in comparison with the salt sensitive genotype.

Combined direct regeneration protocols in tissue culture of different cumin genotypes based on pre-existing meristems.

Rapid and genotype-independent protocols for two direct in vitro morphogenesis pathways including direct shoot organogenesis from embryo and direct shoot proliferation from node have been developed in cumin (Cuminum cyminum L.). Direct regenerations occurring without passing callus phase are important since fewer somaclonal variation and genotype-dependency are likely to arise from these methods in comparison with regenerations trough callus. After embryo culture, shoots with single-cellular origin were regenerated from the meristematic zone of embryo without any intermediate callus phase. In contrast, proliferated shoots with multi-cellular origin were directly regenerated from the axillary buds (meristems) of node explants. Effects of different concentrations of 6-Benzylaminopurine (BAP), alpha-Naphthaleneacetic Acid (NAA) and Indole-3-kcetic Acid (IAA) on B5 medium of embryo and node cultures as well as subculture were studied in detail. In direct organogenesis pathway from embryo explant, 0.1 mg L(-1) NAA + 1 mg L(-1) IAA resulted the highest shoot regeneration response (89.5 shoots per regenerated explant), whereas 0.1 mg L(-1) BAP + 1 mg L(-1) NAA was the most effective combination in direct shoot proliferation from node explant (42 shoots per regenerated explant). BAP (cytokinin) revealed the inhibitory effect on induction of direct shoot organogenesis pathway from embryo explant, while low concentration of BAP (0.1 mg L(-1)) had positive effect on direct shoot proliferation pathway from node explant. Subculturing was not necessary for shoot multiplication and elongation in embryo culture, whereas multiplication and elongation of shoots in node culture were associated to subculture on growth regulator-free medium. In other part of study, the behavior of different cumin genotypes in direct regeneration pathways was studied. Both direct organogenesis and direct proliferation pathways were applicable to different cumin genotypes and regenerated plants were phenotypically normal. This study supports the feasibility of combined direct regenerations protocols from embryo and node of cumin in germplasm conservation by in vitro cloning and genetic improvement programs.