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Plants cannot move, so they have evolved sophisticated strategies that integrate the external environmental cues and internal signaling networks for adaptation to dynamic circumstances. Cis-(+)-12-oxo-phytodienoic acid (OPDA) and 2,3-dinor-OPDA (dn-OPDA), the cyclopentenone-containing oxylipins, ubiquitously occur in the green lineage to orchestrate a series of growth and developmental processes as well as various stress and defense responses. OPDA/dn-OPDA are precursors of jasmonate (JA) biosynthesis in vascular plants. Dn-OPDA and its isomer also serve as bioactive JAs perceived by the coronatine insensitive 1/jasmonate ZIM-domain (COI1/JAZ) co-receptor complex in bryophytes and lycophytes. In addition, OPDA/dn-OPDA display signaling activities independent of (+)-7-iso-jasmonoyl-l-isoleucine (JA-Ile) and COI1 in both vascular and non-vascular plants. In this review, we discuss recent advances in the biosynthesis, metabolism, and signaling of OPDA/dn-OPDA, and provide an overview of the evolution of OPDA/dn-OPDA actions to obtain a deeper understanding of the pervasive role of OPDA/dn-OPDA in the plant life cycle. [ABSTRACT FROM AUTHOR]

Dear Editor, The phytohormone jasmonate (JA), including jasmonic acid and its oxylipin derivatives, is essential for plant resistance against various stresses[1],[2]. Here, we identify I Jasmonate-Induced Dioxygenase1 i ( I JID1 i ) that encodes a 2OGD modifying OPDA and reducing the conversion of OPDA into jasmonic acid and JA-Ile. Interestingly, the amounts of OPDA, jasmonic acid, and JA-Ile in loss-of-function mutants I jid1-1 i and I jid1-5 i were similar to those of WT (Supplementary Figs. [Extracted from the article]

Jasmonate (JA) is one of the key phytohormones essential for plant development and defense processes. The core JA biosynthetic and signaling pathways have been well-characterized. Notably, post-translational modifications (PTMs), which affect the protein structures and functions, have emerged as critical mechanisms to modulate JA output at different spatiotemporal levels. Disruption of PTMs in JA biosynthesis and signaling would cause the dysfunction of vital biological processes. Here, we give an overview of the PTMs that have been identified in JA biosynthetic and signaling pathways, and provide insights into the mechanisms by which PTMs define JA responses. [ABSTRACT FROM AUTHOR]

Main conclusion: The N-myristoylation is required for BSK1 proper plasma membrane targeting and protein turnover. Brassinosteroid (BR) signaling kinase 1 (BSK1), with a myristoylation site at its N-terminus to anchor at plasma membrane (PM), is involved in BR-regulated plant growth and flg22-triggered immunity responses. However, little is known about the role of N-myristoylation in BSK1 protein homeostasis. Here, we revealed that N-myristoylation is critical to the PM targeting and protein stability of BSK1. The N-myristoylation-deficient mutant BSK1G2A mainly distributed in the cytoplasm and retained in the endoplasmic reticulum. We further found that the BSK1G2A proteins were unstable and degraded through ATG8e-labled autophagic pathway. This study provides a new insight into the regulation of plant protein homeostasis. [ABSTRACT FROM AUTHOR]

Chinese fir (Cunninghamia lanceolata) cotyledons are green in darkness due to the coexistence of functional dark-operative protochlorophyllide reductase (DPOR) and light-dependent protochlorophyllide reductase (LPOR). In this study, we found that the POR gene for LPOR and the ChlB, ChlL, and ChlN genes for three DPOR subunits were strongly downregulated in dark-grown new sprouts in which chlorophyll biosynthesis was inhibited. We extracted, sequenced, and annotated the total RNA from etiolated (dark-grown) and green (light-grown) sprouts. A total of 70,499 unigenes were found, of which 47,410 were annotated. Among them, 3263 differentially expressed genes were identified between dark- and light-grown samples. According to the Kyoto Encyclopedia of Genes and Genomes databases, the five most affected metabolic pathways were flavonoid biosynthesis, photosynthesis-antenna proteins, photosynthesis, cutin, suberine and wax biosynthesis and stilbenoid, diarylheptanoid, and gingerol biosynthesis. Based on the acquired cDNA sequences, we applied quantitative PCR to further analyze the relative expression levels of 18 nuclear genes and 11 chloroplast genes related to photophosphorylation. Both transcriptomic and quantitative PCR results indicated that dark treatment can significantly block the expression of all of the identified genes related to the protein complexes of photosynthetic electron flow in new sprouts. Dark treatment of new sprouts of Chinese fir caused etiolation via blockage of the expression of DPOR- and LPOR-encoding genes. Both nuclear and plastid genomic genes related to photosynthesis were significantly downregulated in etiolated sprouts. The results provide new clues to understanding the different mechanisms of chloroplast development in different photosynthetic organs. [ABSTRACT FROM AUTHOR]

Objective Despite heterogeneity among Pacific Islanders, most studies aggregate them regardless of origin. Thus, limited information is available about perinatal outcomes among various subgroups of Pacific Islanders in the United States, including immigrants from the Republic of the Marshall Islands. We sought to evaluate perinatal outcomes among Marshallese women. Methods We conducted a cross-sectional study of women with at least one singleton live birth between 1997 and 2013 in two Arkansas counties using birth certificate data from the Arkansas Department of Health. Unadjusted and adjusted prevalence ratios (PR) and 95% confidence intervals (CI) were calculated from modified Poisson regression models. Results Of the 91,662 singleton births in both counties during the study period, 2488 were to Marshallese women. In adjusted analyses, Marshallese women had higher prevalence of "other medical risk factors" (PR = 1.47; 95% CI 1.30, 1.65) than NH White women. Marshallese women had higher rates of precipitous labor and fetal distress during labor compared to NH White women (PR = 2.65; 95% CI 2.22, 3.17 and 1.89; 95% CI 1.62, 2.21, respectively). Marshallese were also more likely to have tocolysis (PR = 1.43; 95% CI 1.16, 1.76), forceps (PR = 1.68; 95% CI 1.16, 2.43) or vacuum (PR = 1.89; 95% CI 1.60, 2.22) used in delivery and cesarean section (PR = 1.13; 95% CI 1.01, 1.27). Marshallese infants had higher rates of anemia (PR = 3.10; 95% CI 2.01, 4.77), birth injury (PR = 2.13; 95% CI 1.50, 3.03), assisted ventilation < 30 min (PR = 2.11; 95% CI 1.64, 2.71), preterm birth (PR = 1.67; 95% CI 1.50, 1.83), and small-for-gestational age (PR = 1.25; 95% CI 1.12, 1.39) than NH White infants. Conclusions Marshallese women and infants had higher rates of adverse perinatal outcomes compared to their NH White counterparts. Additional studies are needed to determine if perinatal outcomes among the Marshallese differed from other Pacific Islander subgroups. [ABSTRACT FROM AUTHOR]

Biosynthesis and accumulation of jasmonate (JA) can regulate plant defense responses and organ development under insect herbivore stress conditions. One of these responses, the inhibition of root growth, is a common phenomenon. However, the physiological and molecular mechanisms of how JA affects root growth are not completely understood. In this study, the influence of MeJA treatment on auxin and proton flux rates in the root apex region of Col-0, coi1-1, pin2, and aux1-7 mutant lines was examined using a non-invasive micro-test technique. The auxin and H flux profiles taken from coi1-1 mutants suggest that the modulation of auxin and H flux by JA requires the function of COI1. The auxin and H flux in pin2 and aux1 mutants with and without JA treatment suggest that JA can affect polar auxin transport by regulating PIN-mediated auxin efflux and the AUX-mediated influx pathways. Furthermore, the expression levels of PIN1, PIN2, PIN3, PIN7, AUX1, and TIR1 genes were reduced under MeJA treatment, and expression levels of CYP79B2 and CYP79B3 were elevated. Together, these results suggest that JA signaling may modulate the auxin signaling pathways by regulating the expression of key genes. [ABSTRACT FROM AUTHOR]