Belowground ABA boosts aboveground production of DIMBOA and primes induction of chlorogenic acid in maize

Plants are important mediators between above- and belowground herbivores. Consequently, interactions between root and shoot defences can have far-reaching impacts on entire food webs. We recently reported that infestation of maize roots by the root feeding larvae of the beetle Diabrotica virgifera virgifera boosts shoot resistance against herbivores and pathogens. Root herbivory also induced DIMBOA levels and primed for enhanced induction of chlorogenic acid, two secondary metabolites that have been associated with biotic stress resistance. Interestingly, ABA emerged as a putative long-distance signal, possibly responsible for this effect. In this addendum, we investigate the role of root-derived ABA in the systemic regulation of aboveground DIMBOA, and the phenolic compounds chlorogenic acid, caffeic and ferulic acid. We discuss the relevance of the plant hormone in relation to defence against the leaf herbivore Spodoptera littoralis. Soil-drench treatment with ABA mimicked root herbivore-induced accumulation of DIMBOA in the leaves. Similarly, ABA mimicked aboveground priming of chlorogenic acid production, resulting in augmented accumulation of this compound upon subsequent shoot attack by S. littoralis. These findings confirm our notion that ABA acts as an important signal in the regulation of aboveground defence upon belowground herbivory. However, based on our previous finding that ABA alone is not sufficient to trigger aboveground resistance against S. littoralis caterpillars, the results suggest that the ABA-inducible effects on DIMBOA and chlorogenic acid are not solely responsible for root herbivore-induced resistance against S. littoralis. Full text HTML PDF

Respuesta de Vitis vinífera L. cv. Malbec a UV-B y ABA

Malbec es la variedad de uva tinta más importante en la vitivinicultura argentina, especialmente en Mendoza, donde se produce más del 80% del total nacional. Las zonas ubicadas a mayor altitud están experimentando un aumento en la superficie cultivada, ya que en ellas se producen uvas con altos contenidos de compuestos fenólicos, responsables de muchas de las características deseadas en los vinos tintos, por su valor organoléptico y capacidad antioxidante. A partir de estos antecedentes, se plantea como objetivo caracterizar la radiación UV-B que reciben los viñedos ubicados a mayor altitud en Mendoza, estudiando los efectos de UV-B, las aplicaciones de ABA y de su interacción, sobre aspectos fisiológicos y bioquímicos que afectan el crecimiento de las bayas (rendimiento cuantitativo) y la calidad enológica de Vitis vinifera L. cv. Malbec.

Wound Signaling in Tomato Plants1 : Evidence That ABA Is Not a Primary Signal for Defense Gene Activation

The effects of abscisic acid (ABA) on the accumulation of proteinase inhibitors I (Inh I) and II (Inh II) in young, excised tomato (Lycopersicon esculentum L.) plants were investigated. When supplied to excised plants through the cut stems, 100 μm ABA induced the activation of the ABA-responsive le4 gene. However, under the same conditions of assay, ABA at concentrations of up to 100 μm induced only low levels of proteinase-inhibitor proteins or mRNAs, compared with levels induced by systemin or jasmonic acid over the 24 h following treatment. In addition, ABA only weakly induced the accumulation of mRNAs of several other wound-response proteins. Assays of the ABA concentrations in leaves following wounding indicated that the ABA levels increased preferentially near the wound site, suggesting that ABA may have accumulated because of desiccation. The evidence suggests that ABA is not a component of the wound-inducible signal transduction pathway leading to defense gene activation but is likely involved in the general maintenance of a healthy plant physiology that facilitates a normal wound response.

Abañēễme : guía práctica para aprender el idioma guaraní = practical guide for learning the Guaraní tongue = praktischer Führer zur Erlernung des Guaraní.

Paged also in duplicate ([1], iv, iv, 74, 74 p.)

Sifre de-agadeta: ʻal Megilat Ester; halo ̣ hemah ḳevutsat midreshim shonim : Midrash Aba Guriyon, Midrash Panim Aḥarim, Midrash Leḳaḥ Ṭov /

Includes bibliographical references.

Sefer Raban shel kol bene ha-golah : kolel toldot meshakhlel ha-Yahadut ha-Talmudit be-artsot ha-golah Rav o Aba Arikha ... /

"... ʻal-pi shene ha-Talmudim ṿeha-midrashim ṿe-yeter ha-meḳorim sheba-sifrut ha-Talmudit ṿe-ʻal pi ha-ḥaḳirot ha-ḥadashot ʻa. d. ha-goyim, she-ḥayu bi-zemano shel Rav uve-yiḥud ʻa. pi ha-sefer "Divre yeme Paras ha-ḳedumah" le-Dr. Ferdinand Yusṭi.