br Acknowledgments We thank Prof

Acknowledgments We thank Prof. Alexander D. Johnson and Suzanne M. Noble for kindly providing SN strains. This work was supported by Chinese National Natural Science Foundation Grants 31370105 and 31300057, and Shanghai STCSM Grant 12JC1409300.
Introduction Organisms modulate gene expression in response to the environmental variation. Gene expression is controlled by basic components of Raltitrexed mg structures that are regulated by a series of protein complexes leading to specific profiles of chromatin modifications and remodeling. Chromatin remodeling is one of the aspects of rapid transcriptional response that provides transcription factors access to the promoters of corresponding response genes [1]. Histone acetylation that causes chromatin remodeling appears dynamic and reversible, and thereby is a pivotal switch for interchange between permissive and repressive states of chromatin structure. After transfer of acetyl groups from acetyl-CoA to conserved lysine residues with positively charged histone tails, these residues are neutralized and their affinity for negatively charged DNA decreased, which promotes the transcription factors binding to DNA. In addition, transcriptional regulators and chromatin remodeling factors can recognize and bind to the acetylated histone lysine residues. The acetylation of histone lysine residues relax chromatin structure and cause transcriptional activation, on the contrary, weak or no acetylation leads to compaction of chromatin structure and gene repression [2], [3]. HATs catalyzes histone acetylation, whereas histone deacetylases (HDACs) catalyzes histone deacetylation. Much recent work has illustrated that HATs and HDACs are involved in coactivators and corepressor complexes respectively during the gene transcription in yeasts and mammals, which indicates that acetylated histone is an essential part of transcriptional regulatory processes [4], [5], [6], [7]. In eukaryotes, histone acetylation is catalyzed by the Gcn5 (General Control Nonderepressible-5) protein, which is one of components of the multisubunits chromatin remodeling complexes [6], [8]. The SAGA (Spt-Ada-Gcn5-Acetyltransferase) complex is associated with universal transcriptional regulation to modulate gene transcription by recruiting specific gene promoters to alter local chromatin structure [6]. In Saccharomyces cerevisiae, under conditions of environmental stress, such as high temperature, oxidative damage, high osmolarity or nutrient deprivation, the transcription of related gene is regulated by Gcn5. In the fission yeast Schizosaccharomyces pombe, however, Gcn5 has a limited group of stress responses and is only known to be involved in resistance to salt. For these two species, microarray studies have revealed that histone acetylation by the SAGA complex causes chromatin remodeling to regulate transcription of important stress response genes [5], [9]. In animals, the homologs of Gcn5 are important in development, for example the mouse Gcn5 is essential for the embryonic development [10], and in Drosophila, a null allele of the Gcn5 gene lead to the defects in the development of metamorphosis and oogenesis [11]. In Arabidopsis development processes, the histone acetyltransferase Gcn5 is important in cell differentiation, meristem function, leaf and floral organogenesis, and response to light and cold [12], [13]. In Cryptococcus neoformans, the histone acetyltransferase Gcn5 regulates the expression of specific genes to adjust itself respond appropriately to the human host, and the Gcn5 deletion mutants have shown the defects in high-temperature growth and capsule attachment to the cell surface, as well as increased sensitivity to oxidative stress [14]. Oomycete pathogens, such as Phytophthora, possess distinct physiological characteristics and destructive effects causing threat to agriculture and natural ecosystems. The first identified Phytophthora species was Phytophthora infestans, the causal agent of the potato late blight epidemic leading to the Irish potato famine in the middle of the 19th century [15]. Since then, more than 100 species of Phytophthora have been described [16], [17], [18]. Phytophthora species attack a wide range of agriculturally and ornamentally important plants and cause huge damage and economic losses. For example, Phytophthora sojae causes root rot of soybean leading to annual losses at 1–2 billion dollars worldwide [19]. Phytophthora capsici is an important pathogen that causes root, crown, foliar and fruit rot on vegetable growing industry [20].