Diverging cell wall strategies for drought adaptation in two maize inbreds with contrasting lodging resistance.

The plant cell wall is a plastic structure of variable composition that constitutes the first line of defence against environmental challenges. Lodging and drought are two stressful conditions that severely impact maize yield. In a previous work, we characterised the cell walls of two maize inbreds, EA2024 (susceptible) and B73 (resistant) to stalk lodging.

A novel pectin methylesterase inhibitor, PMEI3, in common bean suggests a key role of pectin methylesterification in Pseudomonas resistance.

The mechanisms underlying susceptibility to and defense against Pseudomonas syringae (Pph) of the common bean (Phaseolus vulgaris) have not yet been clarified. To investigate these, 15-day-old plants of the variety Riñón were infected with Pph and the transcriptomic changes at 2 h and 9 h post-infection were analysed. RNA-seq analysis showed an up-regulation of genes involved in defense/signaling at 2 h, most of them being down-regulated at 9 h, suggesting that Pph inhibits the transcriptomic reprogramming of the plant.

Immune Priming Triggers Cell Wall Remodeling and Increased Resistance to Halo Blight Disease in Common Bean.

The cell wall (CW) is a dynamic structure extensively remodeled during plant growth and under stress conditions, however little is known about its roles during the immune system priming, especially in crops. In order to shed light on such a process, we used the - (Pph) pathosystem and the immune priming capacity of 2,6-dichloroisonicotinic acid (INA). In the first instance we confirmed that INA-pretreated plants were more resistant to Pph, which was in line with the enhanced production of HO of the primed plants after elicitation with the peptide flg22.

Perception and First Defense Responses Against pv. in : Identification of Wall-Associated Kinase Receptors.

Common bean () is attacked by several pathogens such as the biotrophic gamma-proteobacterium pv. . To study the pv.

Elucidating compositional factors of maize cell walls contributing to stalk strength and lodging resistance.

Lodging is one of the causes of maize (Zea mays L.) production losses worldwide and, at least, the resistance to stalk lodging has been positively correlated with stalk strength. In order to elucidate the putative relationship between cell wall, stalk strength and lodging resistance, twelve maize inbreds varying in rind penetration strength and lodging resistance were characterized for cell wall composition and structure.

In Vitro Plant Regeneration in Conifers: The Role of and Gene Families.

Conifers are a group of woody plants with an enormous economic and ecological importance. Breeding programs are necessary to select superior varieties for planting, but they have many limitations due to the biological characteristics of conifers. Somatic embryogenesis (SE) and de novo organogenesis (DNO) from in vitro cultured tissues are two ways of plant mass propagation that help to overcome this problem.

The role of cell wall phenolics during the early remodelling of cellulose-deficient maize cells.

The habituation of cultured cells to cellulose biosynthesis inhibitors such as dichlobenil (dichlorobenzonitrile, DCB) has proven a valuable tool to elucidate the mechanisms involved in plant cell wall structural plasticity. Our group has demonstrated that maize cells cope with DCB through a modified cell wall in which cellulose is replaced by a more extensive network of highly cross-linked feruloylated arabinoxylans. In order to gain further insight into the contribution of phenolics to the early remodelling of cellulose-deficient cell walls, a comparative HPLC-PAD analysis was carried out of hydroxycinnamates esterified into nascent and cell wall polysaccharides obtained from non-habituated (NH) and habituated to low DCB concentrations (1.

Determination of abscisic acid and its glucosyl ester in embryogenic callus cultures of Vitis vinifera in relation to the maturation of somatic embryos using a new liquid chromatography-ELISA analysis method.

The levels of abscisic acid (ABA), its conjugate ABA-GE, and IAA were determined in embryogenic calli of Vitis vinifera L. (cv. Mencía) cultured in DM1 differentiation medium, to relate them to the maturation process of somatic embryos.

Rapid responses of C14 clone of Eucalyptus globulus to root drought stress: Time-course of hormonal and physiological signaling.

The responses of juvenile plants of forest crops to drought stress are a key stage in the survival of forest populations. In this work, a suitable experimental system to study the early drought resistance mechanisms and signaling in a drought-tolerant clone (C14) of Eucalyptus globulus Labill is proposed. This system, using hydroponic culture and an osmotic agent, polyethylene glycol 8000, was demonstrated to induce severe stress in the root area, affecting the responses of the plantlets at the aerial level.

Caulogenic induction in cotyledons of stone pine (Pinus pinea): relationship between organogenic response and benzyladenine trends in selected families.

Adventitious bud formation in stone pine cotyledons cultured in the presence of benzyladenine (BA) has been proposed as a model for the study of in vitro shoot organogenesis in conifers. This is because of its advantageous characteristics including the requirement of only one plant growth regulator (BA), the synchronous fashion of its induction, and the homogeneity and low degree of differentiation of cotyledons. Although optimal culture conditions have been developed and are currently in use, we still lack data for BA dynamics in cotyledons cultured under these conditions, and the morphological description of the early induction stages has not, until now, been approached from a histological perspective.

Benzyladenine metabolism and temporal competence of Pinus pinea cotyledons to form buds in vitro.

Germination negatively affects adventitious shoot formation induced by cytokinins in pine cotyledons. To investigate the causes of this decrease in the organogenic response, uptake and metabolism of benzyladenine (BA) were studied in stone pine cotyledons (Pinus pinea) isolated from in vitro germinating embryos and cultured in bud induction medium. As embryos grew, cotyledons showed a progressive decrease in the amount of BA taken up from the medium.

Hormonal changes throughout maturation and ageing in Pinus pinea.

Phytohormones, which are responsible for certain age-related changes in plants, play a major role throughout maturation and ageing. Previous results dealing with this topic allowed us to describe an ageing and vigour index in Pinus radiata based on a ratio between different forms of cytokinins (Cks). The aim of the present study was to extend the studies on the changes in the hormonal status throughout maturation and ageing to Stone pine (Pinus pinea L.

Alterations in endogenous levels of cytokinins following grafting of Pinus radiata support ratio of cytokinins as an index of ageing and vigour.

Markers for ageing or maturation in woody plants provides the possibility of identifying genotypes with a prolonged juvenile phase, or to evaluate reinvigoration procedures, such as grafting of adult material. This study focuses specifically on cytokinins (Cks) as markers, due to their role in the transition process from juvenile to adult states. Previous reports from our group disclosed that the ratio of isopentenyladenine-type (iP-type) to zeatin-type (Z-type) Cks decreases during tree maturation, a maturation and ageing index being likely in Pinus radiata.