Serkan Uranbey

miRNA-based drought regulation in wheat

MicroRNAs (miRNAs) are a class of small non-coding regulatory RNAs that regulate gene expression by guiding target mRNA cleavage or translational inhibition. Drought is a common environmental stress influencing crop growth and development. To date, it has been reported that a number of plant miRNA are involved in drought stress response. In this study, we comparatively investigated drought stress-responsive miRNAs in the root and leaf of bread wheat (Triticum aestivum cv. Sivas 111/33) by miRNA microarray screening. miRNA microarray analysis showed that 285 miRNAs (207 upregulated and 78 downregulated) and 244 miRNAs (115 upregulated and 129 downregulated) were differentially expressed in leaf and root tissues, respectively. Among the differentially expressed miRNAs, 23 miRNAs were only expressed in the leaf and 26 miRNAs were only expressed in the root of wheat growth under drought stress. Upon drought treatment, expression of miR159, miR160, miR166, miR169, miR172, miR395, miR396, miR408, miR472, miR477, miR482, miR1858, miR2118, and miR5049 were found to be significantly differentiated in bread wheat. The regulatory network analysis showed that miR395 has connections with a number of target transcripts, and miR159 and miR319 share a number of target genes. Drought-tolerant and drought-sensitive wheat cultivars showed altered expression pattern upon drought stress in terms of investigated miRNA and their target transcript expression level.

Efficient in vitro bulblet regeneration from immature embryos of endangered Sternbergia fischeriana

Sternbergia fischeriana is an endangered geophyte and therefore in vitro micropropagation of this plant will have great importance for germplasm conservation and commercial production. Bulb scale and immature embryo explants of S. fischeriana were cultured on different nutrient media supplemented with various concentrations of plant growth regulators. Immature embryos produced higher number of bulblets than bulb scales. Large numbers of bulblets were regenerated (over 80 bulblets/explants) from immature embryos on Murashige and Skoog (MS) medium supplemented with 4 mg l−1 6-benzylaminopurine (BA) and 0.25 mg l−1α-naphthaleneacetic (NAA) or 2 mg l−12,4-dichlorophenoxyacetic acid (2,4-D) after 14 months of culture initiation. Regenerated bulblets were kept at 5 °C for 5 weeks and then transplanted to a potting mixture.

Development of high frequency multiple shoot formation in Persian clover (Trifolium resupinatum L.)

An efficient and reliable micropropagation system for Persian clover (Trifolium resupinatum L.) was developed using different explants and media. Node, hypocotyl and cotyledonary node explants were cultured on Murashige and Skoog (MS) medium supplemented with combinations of either 6-benzyladenine (BA) and indole-3-butyric acid (IBA) or BA, Kinetin (KIN) and IBA. Direct multiple shoots developed within 6 weeks in all explants in most media tested. The best shoot multiplication capacity was obtained from cotyledonary node explants on MS medium containing 7.1 μM BA and 1 μM IBA or 14.1 μM BA and 1 μM IBA. Elongated shoots were rooted on either MS medium alone or combination with different concentrations of indole-3-butyric acid (IBA), indole-3-acetic acid (IAA) and α-naphthaleneacetic acid (NAA). High rooting was achieved in half strength MS medium containing 8 μM IBA.

Genome of wild olive and the evolution of oil biosynthesis

Significance We sequenced the genome and transcriptomes of the wild olive (oleaster). More than 50,000 genes were predicted, and evidence was found for two relatively recent whole-genome duplication events, dated at approximately 28 and 59 Mya. Whole-genome sequencing, as well as gene expression studies, provide further insights into the evolution of oil biosynthesis, and will aid future studies aimed at further increasing the production of olive oil, which is a key ingredient of the healthy Mediterranean diet and has been granted a qualified health claim by the US Food and Drug Administration. Here we present the genome sequence and annotation of the wild olive tree (Olea europaea var. sylvestris), called oleaster, which is considered an ancestor of cultivated olive trees. More than 50,000 protein-coding genes were predicted, a majority of which could be anchored to 23 pseudochromosomes obtained through a newly constructed genetic map. The oleaster genome contains signatures of two Oleaceae lineage-specific paleopolyploidy events, dated at ∼28 and ∼59 Mya. These events contributed to the expansion and neofunctionalization of genes and gene families that play important roles in oil biosynthesis. The functional divergence of oil biosynthesis pathway genes, such as FAD2, SACPD, EAR, and ACPTE, following duplication, has been responsible for the differential accumulation of oleic and linoleic acids produced in olive compared with sesame, a closely related oil crop. Duplicated oleaster FAD2 genes are regulated by an siRNA derived from a transposable element-rich region, leading to suppressed levels of FAD2 gene expression. Additionally, neofunctionalization of members of the SACPD gene family has led to increased expression of SACPD2, 3, 5, and 7, consequently resulting in an increased desaturation of steric acid. Taken together, decreased FAD2 expression and increased SACPD expression likely explain the accumulation of exceptionally high levels of oleic acid in olive. The oleaster genome thus provides important insights into the evolution of oil biosynthesis and will be a valuable resource for oil crop genomics.

IN VITRO BULBLET INDUCTION FROM BULB SCALES OF ENDANGERED ORNAMENTAL PLANT MUSCARI AZUREUM

ABSTRACT Muscari azureum with beautiful white and sky blue flowers is an important endangered ornamental plant of Turkey and needs exploitation for commercial propagation. 2–4 bulb scale explants of M. azureum were cultured in basal media supplemented with 2 mg/l 2,4-D, 20 g/l mannitol, 20 g/l sucrose, 0.5 mg/l NAA and different concentrations of BAP, KIN, 2iP and TDZ plus 2 g/l gelrite. The best regeneration on 2 or 4 scales and “the highest mean number of bulblets per explants (mean 8.77per explant)” was achieved on an Orchimax medium supplemented with 2.0 mg/l BAP, 2 mg/l 2,4-D, 20 g/l mannitol, 20 g/l sucrose and 0.5 mg/l NAA for 2-scales. Mature bulblets were excised and individually rooted on half strength MS medium supplemented with 1 mg/l IBA, 0.5 g/l activated charcoal, 20 g/l sucrose and 6 g/l agar. Regenerated plants from 2 and 4 scales were acclimatized with a 14% survival rate after 3 weeks.

Efficient Adventitious Shoot Regeneration in Cicer Milkvetch

ABSTRACT A procedure has been developed for high frequency adventitious shoot regeneration from hypocotyls, cotyledon, stem and petiole explants of cicer milkvetch. All explants isolated from in vitro seedlings were cultured on Murashige and Skoog (MS) media supplemented with various concentrations of 6-benzylaminopurine (BA) and α-naphthaleneacetic acid (NAA) to induce adventitious shoot regeneration. Hypocotyl explants appeared to have better regeneration capacity than stem, cotyledon and petiole explants in most of the media tested. The highest frequency of shoot regeneration was achieved from hypocotyl segments through an initial callus growth on MS medium containing 10 μM BA and 0.1 μM NAA. Regenerated shoots were excised and rooted in half-strength MS medium supplemented with 5.4 μM NAA. Rooted plantlets were acclimatized to ambient conditions and later established under greenhouse conditions.