Jasmonates are a family of oxylipin phytohormones regulating plant development and growth and mediating "defense versus growth" responses. The upstream JA biosynthetic precursor cis-(+)-12-oxo-phytodienoic acid (cis-OPDA) acts independently of CORONATIVE INSENSITIVE 1-mediated JA signaling in several stress-induced and developmental processes. However, its perception and metabolism are only partially understood. An isoleucine analog of the biologically active JA-Ile, OPDA-Ile, was detected years ago in wounded leaves of flowering plants, opening up the possibility that conjugation of cis-OPDA to amino acids might be a relevant mechanism for cis-OPDA regulation. Here, we extended the analysis of amino acid conjugates of cis-OPDA and identified naturally occurring OPDA-Val, OPDA-Phe, OPDA-Ala, OPDA-Glu, and OPDA-Asp accumulating in response to biotic and abiotic stress in Arabidopsis (Arabidopsis thaliana). The OPDA amino acid conjugates displayed cis-OPDA-related plant responses in a JA-Ile-dependent manner. We also showed that the synthesis and hydrolysis of cis-OPDA amino acid conjugates are mediated by members of the amidosynthetase GRETCHEN HAGEN 3 and the amidohydrolase INDOLE-3-ACETYL-LEUCINE RESISTANT 1/ILR1-like families. Thus, OPDA amino acid conjugates function in the catabolism or temporary storage of cis-OPDA in stress responses instead of acting as chemical signals per se.

• MeSH
• amidy metabolismus   MeSH
• Arabidopsis * genetika   metabolismus   MeSH
• cyklopentany * metabolismus   MeSH
• fyziologický stres * MeSH
• homeostáza * MeSH
• isoleucin analogy a deriváty   metabolismus   MeSH
• nenasycené mastné kyseliny * metabolismus   MeSH
• oxylipiny * metabolismus   MeSH
• regulace genové exprese u rostlin MeSH
• regulátory růstu rostlin metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• 12-oxophytodienoic acid MeSH Prohlížeč
• amidy MeSH
• cyklopentany * MeSH
• isoleucin MeSH
• jasmonic acid MeSH Prohlížeč
• nenasycené mastné kyseliny * MeSH
• oxylipiny * MeSH
• regulátory růstu rostlin MeSH

Cannabis sativa L. is an annual herbaceous crop grown for the production of long extraxylary fibers, the bast fibers, rich in cellulose and used both in the textile and biocomposite sectors. Despite being herbaceous, hemp undergoes secondary growth and this is well exemplified by the hypocotyl. The hypocotyl was already shown to be a suitable model to study secondary growth in other herbaceous species, namely Arabidopsis thaliana and it shows an important practical advantage, i.e., elongation and radial thickening are temporally separated. This study focuses on the mechanisms marking the transition from primary to secondary growth in the hemp hypocotyl by analysing the suite of events accompanying vascular tissue and bast fiber development. Transcriptomics, imaging and quantification of phytohormones were carried out on four representative developmental stages (i.e., 6-9-15-20 days after sowing) to provide a comprehensive overview of the events associated with primary and secondary growth in hemp. This multidisciplinary approach provides cell wall-related snapshots of the growing hemp hypocotyl and identifies marker genes associated with the young (expansins, β-galactosidases, and transcription factors involved in light-related processes) and the older hypocotyl (secondary cell wall biosynthetic genes and transcription factors).

• Klíčová slova
• Cannabis sativa, RNA-Seq, bast fibers, cell wall, hypocotyl, immunohistochemistry, phytohormones,
• Publikační typ
• časopisecké články MeSH

Expression takes place for most of the jasmonic acid (JA)-induced genes in a COI1-dependent manner via perception of its conjugate JA-Ile in the SCFCOI1-JAZ co-receptor complex. There are, however, numerous genes and processes, which are preferentially induced COI1-independently by the precursor of JA, 12-oxo-phytodienoic acid (OPDA). After recent identification of the Ile-conjugate of OPDA, OPDA-Ile, biological activity of this compound could be unequivocally proven in terms of gene expression. Any interference of OPDA, JA, or JA-Ile in OPDA-Ile-induced gene expression could be excluded by using different genetic background. The data suggest individual signaling properties of OPDA-Ile. Future studies for analysis of an SCFCOI1-JAZ co-receptor-independent route of signaling are proposed.

• Klíčová slova
• 12-oxo-phytodienoic acid (OPDA), JA-Ile perception, OPDA-Ile-induced gene expression, SCFCOI1-JAZ coreceptor complex, jasmonic acid (JA), jasmonoyl-isoleucine (JA-Ile),
• MeSH
• Arabidopsis metabolismus   MeSH
• cyklopentany metabolismus   MeSH
• isoleucin analogy a deriváty   metabolismus   MeSH
• nenasycené mastné kyseliny metabolismus   MeSH
• oxylipiny metabolismus   MeSH
• proteiny huseníčku metabolismus   MeSH
• regulátory růstu rostlin metabolismus   MeSH
• signální transdukce fyziologie   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• 12-oxophytodienoic acid MeSH Prohlížeč
• cyklopentany MeSH
• isoleucin MeSH
• jasmonic acid MeSH Prohlížeč
• jasmonoyl-isoleucine MeSH Prohlížeč
• nenasycené mastné kyseliny MeSH
• oxylipiny MeSH
• proteiny huseníčku MeSH
• regulátory růstu rostlin MeSH

Oxylipins of the jasmonate family are active as signals in plant responses to biotic and abiotic stresses as well as in development. Jasmonic acid (JA), its precursor cis-12-oxo-phytodienoic acid (OPDA) and the isoleucine conjugate of JA (JA-Ile) are the most prominent members. OPDA and JA-Ile have individual signalling properties in several processes and differ in their pattern of gene expression. JA-Ile, but not OPDA, is perceived by the SCFCOI1-JAZ co-receptor complex. There are, however, numerous processes and genes specifically induced by OPDA. The recently identified OPDA-Ile suggests that OPDA specific responses might be mediated upon formation of OPDA-Ile. Here, we tested OPDA-Ile-induced gene expression in wild type and JA-deficient, JA-insensitive and JA-Ile-deficient mutant background. Tests on putative conversion of OPDA-Ile during treatments revealed only negligible conversion. Expression of two OPDA-inducible genes, GRX480 and ZAT10, by OPDA-Ile could be detected in a JA-independent manner in Arabidopsis seedlings but less in flowering plants. The data suggest a bioactivity in planta of OPDA-Ile.

• MeSH
• Arabidopsis účinky léků   genetika   MeSH
• cyklopentany metabolismus   MeSH
• ekotyp MeSH
• isoleucin analogy a deriváty   metabolismus   MeSH
• listy rostlin účinky léků   metabolismus   MeSH
• messenger RNA genetika   metabolismus   MeSH
• nenasycené mastné kyseliny metabolismus   farmakologie   MeSH
• oxylipiny metabolismus   MeSH
• regulace genové exprese u rostlin účinky léků   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• 12-oxophytodienoic acid MeSH Prohlížeč
• cyklopentany MeSH
• isoleucin MeSH
• jasmonic acid MeSH Prohlížeč
• jasmonoyl-isoleucine MeSH Prohlížeč
• messenger RNA MeSH
• nenasycené mastné kyseliny MeSH
• oxylipiny MeSH

The trap of the carnivorous plant Venus flytrap (Dionaea muscipula) catches prey by very rapid closure of its modified leaves. After the rapid closure secures the prey, repeated mechanical stimulation of trigger hairs by struggling prey and the generation of action potentials (APs) result in secretion of digestive fluid. Once the prey's movement stops, the secretion is maintained by chemical stimuli released from digested prey. We investigated the effect of mechanical and chemical stimulation (NH4Cl, KH2PO4, further N(Cl) and P(K) stimulation) on enzyme activities in digestive fluid. Activities of β-D-glucosidases and N-acetyl-β-D-glucosaminidases were not detected. Acid phosphatase activity was higher in N(Cl) stimulated traps while proteolytic activity was higher in both chemically induced traps in comparison to mechanical stimulation. This is in accordance with higher abundance of recently described enzyme cysteine endopeptidase dionain in digestive fluid of chemically induced traps. Mechanical stimulation induced high levels of cis-12-oxophytodienoic acid (cis-OPDA) but jasmonic acid (JA) and its isoleucine conjugate (JA-Ile) accumulated to higher level after chemical stimulation. The concentration of indole-3-acetic acid (IAA), salicylic acid (SA) and abscisic acid (ABA) did not change significantly. The external application of JA bypassed the mechanical and chemical stimulation and induced a high abundance of dionain and proteolytic activity in digestive fluid. These results document the role of jasmonates in regulation of proteolytic activity in response to different stimuli from captured prey. The double trigger mechanism in protein digestion is proposed.

• MeSH
• buněčný převod mechanických signálů MeSH
• cyklopentany metabolismus   MeSH
• cysteinové endopeptidasy metabolismus   MeSH
• Droseraceae enzymologie   fyziologie   MeSH
• listy rostlin enzymologie   fyziologie   MeSH
• oxylipiny metabolismus   MeSH
• regulátory růstu rostlin metabolismus   MeSH
• rostlinné proteiny metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• cyklopentany MeSH
• cysteinové endopeptidasy MeSH
• jasmonic acid MeSH Prohlížeč
• oxylipiny MeSH
• regulátory růstu rostlin MeSH
• rostlinné proteiny MeSH