Drought stress is major abiotic stress that affects soybean ***,it is widely desirable that soybean becomes more tolerant to *** provide insights into regulatory mechanisms of the stress response,we compared the globa...
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Drought stress is major abiotic stress that affects soybean ***,it is widely desirable that soybean becomes more tolerant to *** provide insights into regulatory mechanisms of the stress response,we compared the global gene expression profiles from leaves of two soybean genotypes that display different responses to water-deficit(BR 16 and Embrapa 48,drought-sensitive and droughttolerant,respectively).After the RNA-seq analysis,a total of 5335 down-regulated and 3170 up-regulated genes were identified in the *** the other hand,the number of genes differentially expressed was markedly lower in the Embrapa 48,355 up-regulated and 471 down-regulated ***,induction and expression of protein kinases and transcription factors indicated signaling cascades involved in the drought ***,the results suggest that the metabolism of pectin is differently modulated in response to drought stress and may play a role in the soybean defense mechanism against *** occurs via an increase of the cell wall plasticity and crosslink,which contributed to a higher hydraulic conductance(Kf)and relative water content(RWC%).The drought-tolerance mechanism of the Embrapa 48 genotype involves remodeling of the cell wall and increase of the hydraulic conductance to the maintenance of cell turgor and metabolic processes,resulting in the highest leaf RWC,photosynthetic rate(A),transpiration(E)and carboxylation(A/Ci).Thus,we concluded that the cell wall adjustment under drought is important for a more efficient water use which promoted a more active photosynthetic metabolism,maintaining higher plant growth under drought stress.
Insecticides cause a range of sub-lethal effects on targeted insects, which are frequently detrimental to them. However, targeted insects are able to cope with insecti- cides within sub-lethal ranges, which vary with ...
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Insecticides cause a range of sub-lethal effects on targeted insects, which are frequently detrimental to them. However, targeted insects are able to cope with insecti- cides within sub-lethal ranges, which vary with their susceptibility. Here we assessed the response of three strains of the maize weevil Sitophilus zeamais Motschulsky (Coleoptera." Curculionidae) to sub-lethal exposure to the pyrethoid insecticide cypermethrin. We ex- pected enzyme induction associated with cypermethrin resistance since it would aid the resistant insects in surviving such exposure. Lower respiration rate and lower activity were also expected in insecticide-resistant insects since these traits are also likely to favor survivorship under insecticide exposure. Curiously though, cypermethrin did not affect ac- tivity of digestive and energy metabolism enzymes, and even reduced the activity of some enzymes (particularly for cellulase and cysteine-proteinase activity in this case). There was strain variation in response, which may be (partially) related to insecticide resistance in some strains. Sub-lethal exposure to cypermethrin depressed proteolytic and mainly cellulolytic activity in the exposed insects, which is likely to impair their fitness. However, such exposure did not affect respiration rate and walking behavior of the insects (except for the susceptible strain where walking activity was reduced). Walking activity varies with strain and may minimize insecticide exposure, which should be a concern, particularly if associated with (physiological) insecticide resistance.
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