Foliar spray of brassinosteroid enhances yield and quality of Solanum lycopersicum under cadmium stress

The presence of cadmium in the soil above a particular level is proposed to check not only plant growth but also productivity and fruit quality. Therefore, in the present study investigations are directed to evaluate the effect of four levels of cadmium (3, 6, 9, 12 mg kg⁻¹) in interaction with two analogs of brassinosteroids on the growth, fruit yield and quality of tomato. Under greenhouse conditions plants were analyzed for antioxidant system activity and photosynthetic assimilation efficiency. Cd stressed plants exhibited poor growth and biological yield. The metal also had a negative impact on the antioxidant system of the resulting fruits. However, the follow up application of BRs (10⁻⁸ M) neutralized the damaging effects of the metal on the plants.     

Bone growth marks reveal protracted growth in New Zealand kiwi (Aves,Apterygidae)

The presence of bone growth marks reflecting annual rhythms in the cortical bone of non-avian tetrapods is now established as a general phenomenon. In contrast, ornithurines (the theropod group including modern birds and their closest relatives) usually grow rapidly in less than a year, such that no annual rhythms are expressed in bone cortices, except scarce growth marks restricted to the outer cortical layer. So far, cyclical growth in modern birds has been restricted to the Eocene Diatryma, the extant parrot Amazona amazonica and the extinct New Zealand (NZ) moa (Dinornithidae). Here we show the presence of lines of arrested growth in the long bones of the living NZ kiwi (Apteryx spp., Apterygidae). Kiwis take 5–6 years to reach full adult body size, which indicates a delayed maturity and a slow reproductive cycle. Protracted growth probably evolved convergently in moa and kiwi sometime since the Middle Miocene, owing to the severe climatic cooling in the southwest Pacific and the absence of mammalian predators.     

Molecular modifications on carboxylic acid derivatives as potent histone deacetylase inhibitors: Activity and docking studies

In the light of known HDAC inhibitors, 33 carboxylic acid derivatives were tested to understand the structural requirements for HDAC inhibition activity. Several modifications were applied to develop the structure–activity relationships of carboxylic acid HDAC inhibitors. HDAC inhibition activities were investigated in vitro by using HeLa nuclear extract in a fluorimetric assay. Molecular docking was also carried out for the human HDAC8 enzyme in order to predict inhibition activity and the 3D poses of inhibitor–enzyme complexes. Of these compounds, caffeic acid derivatives such as chlorogenic acid and curcumin were found to be highly potent compared to sodium butyrate, which is a well-known HDAC inhibitor.     

Effect of 28-homobrassinolide on antioxidant capacity and photosynthesis in Brassica juncea plants exposed to different levels of copper

A sand culture experiment was conducted to study ameliorative role of 28-homobrassinolide (HBL) in Brassica juncea seedlings raised from the seeds treated with water, or 10⁻¹⁰, 10⁻⁸ and 10⁻⁶ M 28-homobrassinolide (HBL) and grown in the presence of copper (50, 100 and 150 mg kg⁻¹ sand) and sampled at 30 days after sowing. The plants grown in the presence of copper exhibited a significant decline in growth, chlorophyll and photosynthetic parameters. However, the activity of antioxidant enzymes: catalase (E.C. 1.11.1.6), peroxidase (E.C. 1.11.1.7) and superoxide dismutase (E.C. 1.15.1.1) and the content of proline increased in the plants grown under copper stress and/or raised from treatment with HBL. However, H₂O₂ content increased significantly in copper-treated plants and decreased in plants given HBL treatment. Treatment of seeds with HBL improved the growth, photosynthetic parameters and antioxidant enzymes and also improved in the plants grown under copper stress. The elevated antioxidant enzyme and proline might be responsible to overcome the toxic effects of copper in B. juncea.     

Mitochondrial DNA diversity in Siberian Tatars of the Tobol-Irtysh basin

Data on the variation of the nucleotide sequence of hypervariable segment I (HVSI) and restriction fragment length polymorphism (RFLP) of the coding region of mitochondrial DNA (mtDNA) have been used to characterize the mitochondrial gene pool of Siberian Tatars of the Tobol-Irtysh basin (N = 218), one of three geographic/linguistic groups of Siberian Tatars. The gene pool of Siberian Tatars has been shown to contain both Asian and European mtDNA lineages at a ratio of 1.0 : 1.5. The mtDNA diversity of Siberian Tatars is substantially higher than that of other Turkic-speaking populations of North and Central Asia. The position of the mitochondrial gene pool of Tatars of the Tobol-Irtysh basin in the genetic space of northern Eurasia populations has been determined.     

From intracellular signaling networks to cell death: the dual role of reactive oxygen species in seed physiology

Reactive Oxygen Species (ROS) are continuously produced during seed development, from embryogenesis to germination, but also during seed storage. ROS play a dual role in seed physiology behaving, on the one hand, as actors of cellular signaling pathways and, on the other hand, as toxic products that accumulate under stress conditions. ROS, provided that their amount is tightly regulated by the balance between production and scavenging, appear now as being beneficial for germination, and in particular to act as a positive signal for seed dormancy release. Such an effect might result from the interplay between ROS and hormone signaling pathways thus leading to changes in gene expression or in cellular redox status. We also propose that changes in ROS homeostasis would play a role in perception of environmental factors by seeds during their germination, and thus act as a signal controlling the completion of germination. However, uncontrolled accumulation of ROS is likely to occur during seed aging or seed desiccation thus leading to oxidative damage toward a wide range of biomolecules and ultimately to necroses and cell death. We present here the concept of the "oxidative window for germination", which restricts the occurrence of the cellular events associated with germination to a critical range of ROS level, enclosed by lower and higher limits. Above or below the "oxidative window for germination", weak or high amounts of ROS, respectively, would not permit progress toward germination.     

Photosynthetic Response of Vigna radiata to Pre-Sowing Seed Treatment with 28-Homobrassinolide

Surface sterilised seeds of mungbean (Vigna radiata L. Wilczek cv. T-44) were soaked in 0, 10⁻⁸, 10⁻⁶, or 10⁻⁴ M aqueous solution of 28-homobrassinolide (HBR) for 4, 8, or 12 h. The treated seeds were grown in sandy loam soil filled in earthen pots and sampled at 30, 40, and 50 d. Net photosynthetic rate, leaf chlorophyll content, carbonic anhydrase activity (E.C. 4.2.1.1), carboxylation efficiency, stomatal conductance, and seed yield at harvest were enhanced by the HBR treatment. The best combination was the pre-sowing seed treatment with 10⁻⁶ M HBR for 8 h. This revised version was published online in August 2006 with corrections to the Cover Date.     

Intracellular delivery of VIP-grafted sterically stabilized phospholipid mixed nanomicelles in human breast cancer cells

The purpose of this study was to determine whether biocompatible and biodegradable vasoactive intestinal peptide-grafted sterically stabilized phospholipid mixed nanomicelles (VIP-SSMM; size, approximately 15 nm), a novel nanosized actively targeted drug delivery platform for breast cancer, accumulate in human MCF-7 breast cancer cells. Using hydrophobic CdSe/ZnS quantum dots (QD), we found that QD-loaded VIP-SSMM accumulated significantly faster and in greater quantity in MCF-7 cells than did QD-loaded SSMM alone (p<0.05). This process was mediated, in part, by VIP receptors because excess human VIP, but not PACAP(6-38) or galanin, significantly attenuated this response (p<0.05). Taken together, these data indicate that VIP-SSMM are actively targeted to human breast cancer cells through VIP receptors. We suggest that VIP-SSMM could be used as an actively targeted nanosized drug delivery platform for breast cancer cells over-expressing VIP receptors.     

A comparative effect of IAA and 4-Cl-IAA on growth,nodulation and nitrogen fixation in <Emphasis Type="Italic">Vigna radiata</Emphasis> (L.) Wilczek

The plants of mung bean (Vigna radiata L. Wilczek) were raised from the seeds soaked in water (control), IAA or 4-C-IAA (10⁻⁶, 10⁻⁸ or 10⁻¹⁰ M) for 8 or 12 h. The plants were allowed to grow in a net house and were sampled at 30 and 45 days after sowing (DAS). Both IAA and 4-Cl-IAA significantly affected the growth (length, fresh and dry mass of roots and shoots), the number of nodules, their fresh and dry mass and the activity of nitrogenase. However, the contents of nitrogen and carbohydrate exhibited a decrease in response to both the auxins. 4-Cl-IAA, at a concentration of 10⁻⁸ M, generated the best response. Moreover, 4-Cl-IAA at other two concentrations (10⁻⁶ and 10⁻¹⁰ M) was much more active than any of the IAA concentration used.