SummaryPhytochrome A (phyA) plays a primary role in initiating seedling de-etiolation and is the only plant photoreceptor known to be activated by far-red light (FR). The signaling intermediate FHY1 appears to either participate directly in relaying the phyA signal or to positively regulate a critical signaling event(s) downstream of phyA activation. Here we identify a homolog of FHY1 named FHL (FHY1-like) as a novel signaling factor essential for complete responsiveness to phyA. FHL possesses functional nuclear localization and nuclear export signals. Lines in which FHL function was abolished by insertional mutagenesis or attenuated by RNAimediated suppression displayed a weaker hyposensitivity to continuous FR than fhy1 null mutants and most reported phyA signaling mutants. However, hypocotyl elongation assays indicated that suppression of FHL expression in fhy1-3 caused an insensitivity of hypocotyl elongation to FR and blue light (B) indistinguishable from that seen in phyA. Real-time PCR indicates that in FR, FHY1 transcripts are approximately 15-fold more abundant than FHL transcripts. Although both FHY1 and FHL are capable of homo-and hetero-interaction via their C-termini, the ability of FHL overexpression to restore wild-type (WT) morphological and molecular phenotypes to fhy1-3 seedlings suggests that the extreme insensitivity to FR associated with suppression of FHL expression in fhy1-3 cannot be accounted for by a critical role for FHY1-FHL heterodimers in phyA signal transmission. Rather, we suggest that the relative abundances of FHY1 and FHL in WT plants account for the differences in the severity of fhy1 and fhl mutations. As for FHY1, FHL transcript accumulation is dependent on FHY3 and is decreased after exposure to FR, R or B light. These findings reiterate the prevalence of partial degeneracy in plant signaling networks that regulate responses crucial to survival.

Zinc nger proteins (ZFPs) play important roles in plant responses to biotic and abiotic stresses. Through microarray analysis, an Oryza sativa L. multi-stress-responsive gene, OsMSR15, was identied and subsequently cloned from rice Pei'ai 64S (Oryza sativa L.). Expression of OsMSR15 was strongly up-regulated by cold, drought and heat stresses in different tissues at different developmental stages of rice. OsMSR15 contains two C2H2-type zinc nger motifs, a nuclear localization signal (B box), a Leu-rich domain (Lbox) and a conserved EAR-motif close to its C-terminus. The OsMSR15-GFP fusion protein was localized to the nucleus. Yeast-one hybrid assay showed that OsMSR15 possesses transcriptional activation ability. Expression of OsMSR15 in Arabidopsis conferred drought tolerance, and transgenic plants showed hypersensitivity to exogenous ABA during the seed germination and post-germination stages. Transgenic plants also showed higher levels of free proline, less electrolyte leakage and increased expressions of a number of stress-responsive genes, including LEA3, RD29A, DREB1A and P5CS1 under drought stress. The obtained results indicate that OsMSR15 is an important regulator involved in plant response to drought stress.

Background China maintains a high overall infant hepatitis B vaccination rate, but there are differences between premature and full-term infants. Premature infants have less physiologic reserve, less external adaptability to stressors, and often delayed vaccination compared to full-term infants - all of which may influence the immune protective effect of vaccination. Every year, 1.2 million premature babies are born in China. Timely vaccination with hepatitis B vaccine is the most effective measure to realize the goal of "zero infections" of hepatitis B virus in all newborns, but there are relatively few investigations of hepatitis B vaccination of preterm infants, leading to uncertainty of coverage and insufficient knowledge of factors influencing timely vaccination of this important population. Methods We obtained HepB vaccination histories for premature infants born between 2019 and 2021 in three provinces from the provincial immunization program information management systems.Extracted data included date of birth, sex, region, and dates of HepB vaccination. We conducted descriptive analyses that included basic characteristics of the study subjects, timely HepB1 vaccination, and full-series HepB vaccination.Factors influencing timely birth dose rated and full series vaccination rate were analyzed by logistic regression. Results There were 1623 premature infants that met inclusion criteria and were included in the final analytic data set. Timely HepB1 birth dose coverage was 71.41%. Premature infants born to mothers with unknown HBsAg status had a timely HepB1 birth dose rate of 69.57%. Timely HepB1 vaccination was higher at county level and above hospitals(72.02%) than hospitals below the county level(61.11%).The full-series HepB vaccination rate was 94.15%,but the full coverage rate of preterm infants weighing less than 2000g at birth was 76.92%.Logistic regression analysis of factors influencing timely HepB1 vaccination showed that the HepB1 timely vaccination rate was positively associated with being born to a HBsAg positive mother and being preterm with high birth weight, but was negative associated with being born to a mother with unknown HBsAg status. Regression analysis for factors influencing full-series HepB coverage showed that being born prematurely was positively associated, and being premature with a very low birth weight was negatively associated with full-series HepB coverage. Conclusions Timely HepB1 birth dose coverage in three provinces of China was less than the target of 90%,especially in the Premature infants born to mothers with unknown HBsAg status and at hospitals below the county level.Screening of pregnant women should be a universal normal standard. Hepatitis B vaccination training should be strengthened in hospitals to improve the timely HepB birth dose vaccination rate of premature infants and to effectively prevent mother-to-child transmission of hepatitis B virus.