Project description:The OsbZIP23 transcription factor has been characterized for its essential role in drought resistance in rice, but the mechanism is unknown. Here, we performed genome-wide identification of OsbZIP23 targets by immunoprecipitation sequencing (ChIP-seq) and RNA Sequencing (RNA-Seq) analyses in the OsbZIP23-overexpression, osbzip23 mutant, and wild-type rice under normal and drought stress conditions. OsbZIP23 directly regulates a large number of reported genes that function in stress response, hormone signaling, and developmental processes. Among these targets, we found that OsbZIP23 could positively regulate OsPP2C49, and overexpression of OsPP2C49 in rice resulted in significantly decreased sensitivity of the ABA response and rapid dehydration. Moreover, OsNCED4 (9-cis-epoxycarotenoid dioxygenase 4), a key gene in ABA biosynthesis, was also positively regulated by OsbZIP23. Together, our results suggest that OsbZIP23 acts as a central regulator in ABA signaling and biosynthesis, and drought resistance in rice.
Project description:The prothoracicotropic hormone (PTTH) is a well-known neuropeptide that regulates insect metamorphosis (the juvenile-to-adult transition) by inducing the biosynthesis of steroid hormones, similar to the hypothalamic-pituitary-gonadal control of mammalian puberty. However, the role of Ptth in adult physiology and longevity is largely unexplored. Here, we show that Ptth loss-of-function mutants are long-lived and exhibit increased resistance to oxidative stress in Drosophila. Intriguingly, we find that loss of Ptth blunt age-dependent upregulation of NF-κB signaling specifically in fly oenocytes, the homolog of mammalian hepatocytes. We further show that oenocyte-specific overexpression of NF-κB/Relish blocks the lifespan extension of Ptth mutants, suggesting that Ptth regulates lifespan through oenocyte-specific NF-κB signaling. Surprisingly, adult-specific knockdown of Ptth did not prolong lifespan, indicating that Ptth might control longevity through developmental programs. Our developmental transcriptomic analysis reveals an interesting activation of NF-κB signaling during fly metamorphosis, which is attenuated in Ptth mutants. Intriguingly, the knockdown of NF-κB/Relish, specifically in oenocytes during metamorphosis, significantly prolongs the lifespan of adult flies. Thus, our findings uncover an unexpected role of insect hormone PTTH in controlling adult lifespan through temporal and spatial activation of NF-κB signaling in developing hepatocytes.
Project description:The prothoracicotropic hormone (PTTH) is a well-known neuropeptide that regulates insect metamorphosis (the juvenile-to-adult transition) by inducing the biosynthesis of steroid hormones, similar to the hypothalamic-pituitary-gonadal control of mammalian puberty. However, the role of Ptth in adult physiology and longevity is largely unexplored. Here, we show that Ptth loss-of-function mutants are long-lived and exhibit increased resistance to oxidative stress in Drosophila. Intriguingly, we find that loss of Ptth blunt age-dependent upregulation of NF-κB signaling specifically in fly oenocytes, the homolog of mammalian hepatocytes. We further show that oenocyte-specific overexpression of NF-κB/Relish blocks the lifespan extension of Ptth mutants, suggesting that Ptth regulates lifespan through oenocyte-specific NF-κB signaling. Surprisingly, adult-specific knockdown of Ptth did not prolong lifespan, indicating that Ptth might control longevity through developmental programs. Our developmental transcriptomic analysis reveals an interesting activation of NF-κB signaling during fly metamorphosis, which is attenuated in Ptth mutants. Intriguingly, the knockdown of NF-κB/Relish, specifically in oenocytes during metamorphosis, significantly prolongs the lifespan of adult flies. Thus, our findings uncover an unexpected role of insect hormone PTTH in controlling adult lifespan through temporal and spatial activation of NF-κB signaling in developing hepatocytes.