In this study, the effect of Plant Growth Regulators (PGRs) [6-Benzylaminopurine (BAP) (0, 1.0, 2.0, 3.0 mg L-1) alone and BAP in combinations with α-Naphthaleneacetic acid (NAA) (0, 0.05, 0.10, 0.15 mg L-1) or Indole-3-butyric acid (IBA) (0, 0.01, 0.05, 0.10 mg L-1)] on direct organogenesis from hypocotyl and cotyledon explants of 4-5-week-old sterile seedlings of Liquidambar orientalis (Oriental sweetgum) were investigated. For organogenesis, the addition of BAP to the medium was required, also the combinations of BAP with NAA responded better in terms of the percentage of shoot-forming explants, the number of shoots per explant and the growth of shoots as compared to combinations of BAP with IBA. The highest average percentage of shoot formation (76.64%) was obtained from hypocotyl explants cultured on Woody Plant Medium (WPM) containing 0.10 mg L-1 NAA + 3.0 mg L-1 BAP. The highest average shoot number per explant (32.20 shoots/explant) was observed in also hypocotyl explants cultured on WPM supplemented with 0.10 mg L-1 IBA + 1.00 mg L-1 BAP. The combination of 0.05 mg L-1 NAA + 1.0 or 2.0 mg L-1 BAP was found to be appropriate for both explants.

Iridaceae familyasına ait olan Crocus sativus L. triploid (2n=3x=24) bir bitkidir ve korm (corm)'ları aracılığı ile vejetatif olarak çoğaltılmaktadır. Crocus sativus çiçeklerinin stigmaları bitkinin ekonomik olarak en önemli kısmını oluşturmakta ve hem kuru stigmalarından elde edilen baharat hem de bitkinin adı safran olarak isimlendirilmektedir. Safran bitkisi kokusunu safranal, tadını pikrokrosin, rengini ise krosin adı verilen sekonder bileşiklerinden almakta olup bu metabolitleri stigmasında bulundurmaktadır. Safranın ekonomik değeri, boya, gıda ve kozmetik gibi çeşitli endüstri dallarında çok geniş kullanım alanının yanı sıra sekonder metabolitlerinin sahip olduğu anti-kanser özelliğinden ileri gelmektedir. Kormların çoğalma oranının yüksek olmaması ve patojenlerle bulaşık olma durumu safran üretimini kısıtlamakta ve kaliteyi düşürmektedir. Bu olumsuzluklar ve yetiştirme zorlukları nedeniyle yıllık safran üretiminin giderek azalması ve safran ihtiyacının karşılanamaması, araştırmaları safranın in vitro çoğaltımı üzerine yoğunlaştırmıştır. İn vitro kültür gibi biyoteknolojik yöntemler; safran bitkisi için kısa sürede büyük miktarlarda çoğaltım materyali elde etmeyi sağlamakta ayrıca, krosin, pikrokrosin ve safranal gibi ticari öneme sahip kimyasal maddelerin üretimi için de imkan sunmaktadır. Bu makalede, safranın başlıca sekonder metabolitleri ve in vitro kültürü üzerine yapılan bazı çalışmalar derlenmiştir.

Brassinosteroids (BRs) are steroid phyotohormones that play roles in plant growth, secondary metabolite accumulation, stress response, and adaptation. Saffron (Crocus sativus L.) is an important plant with significant pharmacological effects due to its rich phytochemical content. Crocin, the main pigment of the saffron stigma, is a natural food colorant and has anti-cancer activity. In this study, the effects of 24-Epibrassinolide (EBL) at different concentrations (10-6 , 10-7 , 10-8 and 10-9 M) on corm (mother corm) and aerial part related parameters as well as the level of crocin in saffron were investigated. The experiment was conducted in a plant growth cabinet as randomized plots design with 3 replications. 24-Epibrassinolide treatments did not affect the rates of shoot emergence from saffron corms, while 10-8 and 10-9 M EBL treatments increased the number of active nodium and cormlet (daughter corm) as compared to control. All the applied EBL concentrations significantly increased the root and shoot lengths of saffron plants. The maximum number of flowers per plant was observed as a result of the 10-8 M EBL treatment. Exogenous treatment of 10-9 M EBL enhanced the crocin level by 96.0% compared to the control. This is the first study to evaluate the effects of BRs in saffron.

Deficiency or excess of boron in the soil may be an important abiotic stress factor. Seven different superoxide dismutase (SOD) isoforms including Cu/ZnSOD (CSD1, CDS2, CSD3), FeSOD (FSD1, FSD2, FSD3), and MnSOD (MSD1) genes have been identified in Arabidopsis thaliana. The aim of this study is to determine the expression levels of the genes encoding superoxide dismutase, which is the key enzyme of the antioxidant system, in leaf and root tissues of Arabidopsis thaliana (L.) under boron (B) deficiency or toxicity conditions using Real-Time PCR. Arabidopsis plants were grown in hydroponic culture system for six weeks and incubated for 48 hours in mediums excluding boric acid (BA) (0 µM) or including high concentration of BA (3000 µM). B stress tretaments increased the expression levels of the CSD1 and FSD3 genes in leaf tissue. mRNA level of MSD1 gene is increased in result of B toxicity application in leaf tissue, while B deficiency application increased the mRNA level in root tissue. B deficiency and toxicity treatments altered the expression levels of the CSD2, FSD1, and FSD2 genes depending on the tissue. In conclusion, it has been revealed that B stress triggers antioxidative defense mechanisms in different cellular compartments in roots and leaves.