( Alcázar et al., 2010 ; Gill & Tuteja, 2010 ; Shi et al., 2010 ). It has been demonstrated that PAs are also involved in the tolerance of plants to abioticstresses because the accumulation of PAs is enhanced under stressful conditions ( Fariduddin et
Authors:Shagufta Perveen, Muhammad Iqbal, Muhammad Saeed, Naeem Iqbal, Sara Zafar, and Tehmina Mumtaz
amino acids has been considered as a promising approach to improve the growth of crop plants ( Teixeira et al., 2017 ). Under abioticstresses, foliar application of N -acetyle-cysteine (Cys) alleviated the adverse effects of salt stress ( Genisel et
silicate on Fusarium sulphureum and its effect on dry rot of potato tubers . J. Food Sci. 74 , M213 – M218 .
Liang , Y. , Sun , W. , Zhu , Y. G. and Christie , P. ( 2007 ): Mechanisms of silicon-mediated alleviation of abioticstresses in
Mackill, D.J. 2006. Breeding for resistance to abioticstresses in rice: the value of quantitative trait loci. In: Lamkey, K.R., Lee, M. (eds), Plant Breeding. Blackwell Publishing, pp. 201–212.
Mackill, D.J., Amante
Among the abiotic stress factors influencing the growth and productivity of wheat varieties, extremely high temperatures have the most limiting effect. In an experiment set up in the gradient chamber of the Martonvásár phytotron to test the effect of various temperatures on four winter wheat varieties and one variety of spelt, substantial differences were observed in the heat stress tolerance of the varieties. There was a considerable reduction in the number of shoots and spikes as the result of heat stress, leading to a drastic loss of grain yield. It was clear from changes in the biomass and in the grain:straw ratio that extremely high temperatures led to a substantial reduction in the ratio of grain to straw in the varieties tested. In response to high temperature the wheat plants turned yellow earlier due to the rapid decomposition of the chlorophyll content. This resulted in a considerable shortening of the vegetation period and early ripening. Reductions in the parameters tested were observed at different temperature levels for each variety, indicating considerable differences in the ability of the varieties to adapt to abiotic stress factors.
Authors:A. Comeau, F. Langevin, V. Caetano, S. Haber, M. Savard, H. Voldeng, G. Fedak, Y. Dion, S. Rioux, J. Gilbert, D. Somers, and R. Martin
It has proven to be an enduring and difficult challenge to generate useful germplasm that resists fusarium head blight (FHB) as effectively as Sumai 3. While focussed genetic approaches may follow a clear path to a well-defined goal of resistance, they run the risk of worsening traits not selected for. It was commonly believed that selecting for good performance under pressure from multiple diseases plus abiotic stress should be a harder task than focussing on the single goal of FHB resistance; and yet the complex, systemic approaches have now been shown to be capable of rapid progress. Moreover, the risks of worsening non-selected traits are lessened, because the selection matrices favour genes, or groups of genes, that are free of major defects arising from linkage or pleiotropy. However, even at the pre-breeding level, environments are needed that stress the tested germplasm abiotically and with multiple diseases, as a broad array of traits must be examined at the same time. Since as much as 98–99% of any population may need to be discarded, the widest possible genetic range of diversity should be investigated. As seen in several bread wheat examples, the critical factors that allow for rapid selection of germplasm resistant to most stresses are: a) use of an extensive range of available biodiversity; b) well-designed planning of numerous crosses; c) the astute application of combinations of biotic and abiotic stresses; and d) fast recycling of multiple-resistant lines into crossing blocks. Analyses of our first attempts (2003–07) with such systemic approaches show that as early as F1-F3, germplasm with minimal defects and resistant to the multiple biotic and abiotic stresses can be selected. This ability to identify and advance trait packages rather than just individual traits also improves efficiency for breeders. The selected germplasm resisted well all diseases of concern in Eastern Canada: FHB, barley yellow dwarf (BYD), rusts, powdery mildew, leaf spots, and root diseases. The best (e.g. FL62R1) had FHB resistance near equivalent to Sumai 3 while displaying good yield potential and agronomic traits. Milling quality still falls short of desired levels, but was a good improvement over Sumai 3. The systemic approach, so described because it integrates the pursuit of multiple traits in complex environments, has now demonstrated, in a Canadian setting, the success achieved earlier in Brazil. This confirmation and extension of the utility of systemic approaches support the case for their wider application.
In order to target factors involved in plant-pathogen interactions, gene expression differences were investigated on pepper (
L.) plants after artificial infection with the bacterial pathogen
. Amplified Fragment Length Polymorphism investigations on reverse transcribed DNA fragments (cDNA-AFLP) were used to compare the expression profiles of parental lines and of resistant and susceptible individuals from pepper populations segregating for the
gene, which confers a general defence system in pepper. In total, 73 transcript-derived fragments (TDFs) displaying differential expression patterns could be identified (presence-absence and/or different time courses in resistant and susceptible genotypes). Of these, 67 fragments were cloned and sequenced. In the case of several TDFs, sequence comparisons revealed close homologies to genes known to be responsible for abiotic stress or biotic elicitors, presenting potentially interesting targets for more detailed studies on gene expression and signal transduction.
Sanita di Toppi, L. and Pawlik-Skowronska, B. (eds) (2003): Abiotic stresses in plants. - Kluwer Academic Publishers, Dordrecht, The Netherlands, 231 pp. (ISBN 1-4020-1648-4); Weber, E. (2003): Invasive plant species of the world: A reference guide to environmental weeds. - CAB International Publishing, Wallingford, 548 pp. (ISBN 0-85199-695-7); Werum, M. and Lange-Bertalot, H. (2004): Diatoms in springs from Central Europe and elsewhere under the influence of hydrogeology and anthropogenic impacts. pp. 9-417. Reichardt, E. (2004): Eine bemerkenswerte Diatomeenassoziation in einem Quellhabitat im Grazer Bergland, Österreich. pp. 419-480. - In: Lange-Bertalot, H. (ed.): Iconographia Diatomologica. Annotated Diatom Micrographs. Vol. 13. Ecology-Hydrogeology-Taxonomy. A. R. G. Gantner Verlag K. G. Ruggel, 480 pp.;
Authors:N.V. Trubacheeva, E.D. Badaeva, T.S. Osadchaya, and L.A. Pershina
Wild barley, Hordeum marinum subsp. gussoneanum (2n = 28) is a valuable source of genes that determine resistance to abiotic stresses. These resistance traits might be transferred to wheat due to the crossability of wild barley with bread wheat. The availability of reliable and rapid methods for the identification of H. marinum subsp. gussoneanum chromatin in a wheat background would facilitate the development of introgression wheat genotypes. For this purpose, we evaluated the applicability of eighty-seven H. vulgare EST markers for studying bread wheat – H. marinum subsp. gussoneanum substitution and addition lines. Of all of the markers studied, forty-three (49%) were amplified in H. marinum ssp. gussoneanum and wheat introgression lines. The identification of wild barley chromosomes using EST markers confirmed the GISH and C-banding data. Thus, it was established that the H. vulgare EST markers can be successfully used to identify the chromosomes of the H. marinum subsp. gussoneanum in introgression lines of wheat.
Authors:Y. Li, K. Zhou, M. Jiang, B. Zhang, M. Aslam, and H. Zou
Numerous studies showed that lipid transfer proteins (LTPs) play important roles in flower, development, cuticular wax deposition and pathogen responses; however, their roles in abiotic stresses are relatively less reported. This study characterized the function of a maize LTP gene (ZmLTP3) during drought stress. ZmLTP3 gene was transferred into maize inbred line Jing2416; subsequently the glyphosate and drought tolerance of the over-expression (OE) lines were analyzed. Analysis showed that OE lines could significantly enhance drought tolerance. Transgenic maize lines OE6, OE7 and OE8 showed lower cell membrane damage, higher chlorophyll contents, higher protective enzymes activities, better growth and development under drought condition. The results strongly indicated that overexpression of ZmLTP3 could increase drought tolerances in maize.