Molecular Cloning and Functional Analysis of GmLACS2-3 Reveals Its Involvement in Cutin and Suberin Biosynthesis along with Abiotic Stress Tolerance

Cutin and wax are the main precursors of the cuticle that covers the aerial parts of plants and provide protection against biotic and abiotic stresses. Long-chain acyl-CoA synthetases (LACSs) play diversified roles in the synthesis of cutin, wax, and triacylglycerol (TAG). Most of the information concerned with LACS functions is obtained from model plants, whereas the roles of LACS genes in Glycine max are less known. Here, we have identified 19 LACS genes in Glycine max, an important crop plant, and further focused our attention on 4 LACS2 genes (named as GmLACS2-1, 2, 3, 4, respectively). These GmLACS2 genes display different expression patterns in various organs and also show different responses to abiotic stresses, implying that these genes might play diversified functions during plant growth and against stresses. To further identify the role of GmLACS2-3, greatly induced by abiotic stresses, we transformed a construct containing its full length of coding sequence into Arabidopsis. The expression of GmLACS2-3 in an Arabidopsis atlacs2 mutant greatly suppressed its phenotype, suggesting it plays conserved roles with that of AtLACS2. The overexpression of GmLACS2-3 in wild-type plants significantly increased the amounts of cutin and suberin but had little effect on wax amounts, indicating the specific role of GmLACS2-3 in the synthesis of cutin and suberin. In addition, these GmLACS2-3 overexpressing plants showed enhanced drought tolerance. Taken together, our study deepens our understanding of the functions of LACS genes in different plants and also provides a clue for cultivating crops with strong drought resistance.

Intra- and inter-cultivar genetic variability in Bulgarian tobacco

PURPOSE: The genus Nicotiana is a well-defined group of species of which tobacco (Nicotiana tabacum L.) is the most important crop plant and plays a significant role in the economies of many countries. Recent advances in molecular genetics of the crop allowed the identification of many important genes and their location on chromosomes. However, the genetic analysis of this inbreeding, highly homozygous plant that serves as a model in many other studies is still very much work in progress. METHODS: A large proportion of the tobacco genome is represented by highly repeated DNA sequences, which makes molecular markers, based on them, an obvious first choice in diversity studies. Here we present an assessment with Inter-Simple Sequence Repeat (ISSR) markers of the intra- and inter-cultivar variability in a set of Bulgarian tobacco varieties. RESULTS: The screening of the 4 primers revealed a varying number of bands generated by different primers. The total number of bands varied between 4 and 13. No correlation between the total number of bands and the number of polymorphic bands was observed. Testing with ISSR primers revealed that plants with different DNA profiles can be found in varieties used. The highly similar profiles when E7 primer was used in two of the tested varieties from different production types indicate that the DNA fingerprinting technique may present a particular challenge in this crop. CONCLUSIONS: The present study demonstrates the power of the ISSR technique as a tool for diversity identification in tobacco.

Is callose required for silicification in plants?

The cell wall polymer callose catalyses the formation of silica in vitro and is heavily implicated in biological silicification in Equisetum (horsetail) and Arabidopsis (thale cress) in vivo . Callose, a β-1,3-glucan, is an ideal partner for silicification, because its amorphous structure and ephemeral nature provide suitable microenvironments to support the condensation of silicic acid into silica. Herein, using scanning electron microscopy, immunohistochemistry and fluorescence, we provide further evidence of the cooperative nature of callose and silica in biological silicification in rice, an important crop plant and known silica accumulator. These new data along with recently published research enable us to propose a model to describe the intracellular events that together determine callose-driven biological silicification.

Allium ramosum L. (Amaryllidaceae), a neglected alien in the European flora and its oldest record from Poland

Allium ramosum Linnaeus (1753: 296) is a wild relative of A. tuberosum Rottler ex Sprengel (1825: 38), an important crop plant from East Asia (Blattner & Friesen 2006), while A. ramosum sometimes is cultivated as a vegetable in north-eastern China (Choi & Oh 2011). Both species belong to a small section A. sect. Butomissa (Salisbury 1866: 91) Kamelin (1973: 239), which is subordinated to a subgenus of the same name, A. subgen. Butomissa (Salisb.) N.Friesen in Friesen et al. (2006: 22).

Operational performance of the mechanized and semi-mechanized potato harvest

Potato is an important crop plant throughout the world. Harvesting is a fundamental step in its production system. Maybe, it is the most complex and expensive operation. Thus, the objective of this work was to compare the cost of the mechanized and semi-mechanized harvest, the operational capacity and the production losses during the potato harvest process. The work was accomplished in a commercial farming, cultivated under pivot system, in the municipal district of Perdizes - MG, Brazil. A completely randomized design with two treatments was used: mechanized and semi-mechanized harvest. The mechanized harvest used a self-propelled harvester. In the semi-automated harvest, a digger mounted on tractor was used and the potato was manually harvested. It was concluded that the cost of mechanized harvest was 49.03% lower than the cost of semi-mechanized harvest. On average, the harvester had a work for 23 workers in manual harvest. Mechanized harvest showed losses of 2.35% of potato yield, while the semi-mechanized harvest showed losses of 6.32%.