Role of PfGCN5 in nutrient sensing and transcriptional regulation in Plasmodium falciparum

Malaria is a deadly, infectious disease caused by the parasite Plasmodium, leading to millions of deathsworldwide. Plasmodium requires a coordinated pattern of sequential gene expression for surviving in bothinvertebrate and vertebrate host environments. As parasites largely depend on host resources, they also developefficient mechanisms to sense and adapt to variable nutrient conditions in the environment and modulate theirvirulence. Earlier we have shown that PfGCN5, a histone acetyltransferase, binds to the stress-responsive andvirulence-related genes in a poised state and regulates their expression under temperature and artemisinintreatment conditions in P. falciparum. In this study, we show upregulation of PfGCN5 upon nutrient stresscondition. With the help of chromatin immunoprecipitation coupled high-throughput sequencing (ChIP-seq)and transcriptomic (RNA-sequencing) analyses, we show that PfGCN5 is associated with the genes that areimportant for the maintenance of parasite cellular homeostasis upon nutrient stress condition. Furthermore, weidentified various metabolic enzymes as interacting partners of PfGCN5 by immunoprecipitation coupled withmass spectroscopy, possibly acting as a sensor of nutrient conditions in the environment. We also demonstratedthat PfGCN5 interacts and acetylates PfGAPDH in vitro. Collectively, our data provides important insights intotranscriptional deregulation upon nutrient stress condition and elucidate the role of PfGCN5 during nutrientstress condition.

Discrimination of population of recombinant inbred lines of rye (Secale cereale L. ) for different responses to nitrogen-potassium stress assessed at the seedling stage under in vitro conditions

Background: Plants differ in the methods used to acquire nutrients from environments with low nutrient availability, and may change the morphology of their ‘root architecture’ to be able to take up nutrients. Results: In the present study rye response to stress caused by high and low nitrogen-potassium treatments in mature embryos cultures was described within a population consisting of one hundred and thirty eight recombinant inbred lines of rye. Characterization of the response of recombinant inbred lines (RILs) to nutrient stress was presented as the results of analyses of morphological traits, and physiological and biochemical parameters of the seedlings grown in both treatments. A wide range of variability of individual RILs to induced stress was observed in the population of recombinant inbred lines, and was presented as the difference between the means of each of the analysed traits described at high- and low-nitrogen-potassium levels. Lines were grouped using Ward's agglomerative method on the basis of differences in coleoptyle length, with the longest root length and root number used as variables. Conclusions: Recombinant inbred lines at low nitrogen-potassium treatment developed: longer, shorter, or roots of similar length in comparison with the high nitrogen-potassium treatment. Discriminant function analysis showed that the discriminant variable able to clearly differentiate recombinant inbred lines in terms of their response to nutrient stress was the trait of the longest root length.