Tagged: phytohormones



Salicylic acid-independent responses in PI4K mutants

Arabidopsis thaliana is the lab rat of plant sciences. Mutants tweaked in certain genes can show the effects of hormones on plants, but it can be hard to change one response without changing some others. How do plants work? A common method to find out what the various things inside a plant do is to get a mutant and test it against a known plant to see what the mutant effects are. Arabidopsis thaliana is the go-to plant for this kind of work. It has a small, well-known genome. It also has a large number of people working on it,...

Continue reading Salicylic acid-independent responses in PI4K mutants

Defence signalling marker gene responses to hormonal elicitation differ between roots and shoots

Plants responses to environmental stresses are regulated by signalling hormones, such as jasmonic acid, salicylic acid, ethylene and abscisic acid. Plant scientists commonly use marker genes to study which signalling pathways are activated, however, these markers were designed and tested for shoot responses in Arabidopsis thaliana. It is unclear whether the paradigms based on experiments on above-ground organs of A. thaliana are entirely transferable to shoots and roots of other species. A recent study by Papadopoulou et al. published in AoB PLANTS investigated the regulation dynamics of hormonal-related marker genes in both roots and shoots of the non-model plant Brassica rapa. The...

Continue reading Defence signalling marker gene responses to hormonal elicitation differ between roots and shoots

Brachypodium

Functional drought response in the Brachypodiumdistachyon species complex

Some polyploid species show enhanced physiological tolerance to drought compared with their progenitors. However, very few studies have examined the consistency of physiological drought response between genetically differentiated natural polyploid populations, which is key to evaluating the importance of adaptive evolution after polyploidization in those systems where drought exerts a selective pressure. Martínez et al. used a comparative functional approach to investigate differentiation of drought-tolerance-related traits in the Brachypodium species complex, a model system for grass polyploid adaptive speciation and functional genomics that comprises three closely related annual species: the two diploid parents, B. distachyon and B. stacei, and the...

Continue reading Functional drought response in the Brachypodiumdistachyon species complex

Model summarizing the main anatomical, phytohormonal and proteomical changes observed in the convex and concave sides of three bent taproot sectors

Asymmetric responses of the woody poplar taproot axis to bending stress

Mechanical bending stress can result in cell wall strengthening and increased wood formation across root axes together with an attendant asymmetrical accumulation of phytohormones. De Zio et al. show how different mechanical force intensities act across the compressed concave and stretched convex sides of the woody bent poplar taproot. The results show that, in contrast to the response of the poplar stem, bending stress applied to woody poplar taproots results in increased wood formation toward the concave side (compressed zone), characterized by the highest values of quantity of cambial cells, xylem thickness and lignin content. The highest quantity of lateral...

Continue reading Asymmetric responses of the woody poplar taproot axis to bending stress

Chitin-induced nepenthesin activity in the pitcher fluid of Nepenthes alata.

Prey-induced responses in carnivorous Nepenthes

Carnivorous plants of the genus Nepenthes catch and digest prey, mainly arthropods, in their pitcher traps in order to obtain additional nutrients such as nitrogen and phosphate. The digestive character of the pitcher fluid is well known; other features of the fluid are less well understood, in particular the induction and regulation of its composition. Here, Yilamujiang et al. study the induction of both phytohormones and digestion-related genes in the pitcher of Nepenthes alata. The authors demonstrate that insect prey as well as chitin is able to induce first jasmonate phytohormones which in turn can induce genes for digestive enzymes...

Continue reading Prey-induced responses in carnivorous Nepenthes

Aldrovanda vesiculosa

Polar growth and the development of aquatic carnivorous plants

Cytokinin and auxin biosynthesis and distribution patterns have been studied intensively in many terrestrial plant species. Until now, no direct phytohormonal screening has been carried out in rootless, aquatic, carnivorous plants. Šimura et al. present here insight into cytokinin and auxin levels, their distribution and relative abundance in segmented shoots and turions of Aldrovanda vesiculosa and Utricularia australis, which exhibit very rapid apical growth with simultaneous senescence of basal parts of shoots. Although both species showed similar trends in basipetal decrease of active cytokinins and in the cytokinin-to-auxin ratio, our detailed metabolic analysis revealed interesting differences in the cytokinin regulation.

Continue reading Polar growth and the development of aquatic carnivorous plants

Post-harvest transcriptional changes in onion

Post-harvest transcriptional changes in onion

During the transition from endo- to eco-dormancy and subsequent growth, the bulb of onion (Allium cepa) changes from a sink organ to a source, but the mechanisms controlling these processes are not fully understood. Chope et al. carry out detailed analysis of whole-bulb physiology, biochemistry and transcriptional changes in response to sprouting and provide evidence that the monosaccharide-to-disaccharide ratio and zeatin riboside concentration are important factors in discriminating between sprouting and pre-sprouting bulbs. The results also suggest that commercial curing temperatures could be reduced without detrimental effects.

Continue reading Post-harvest transcriptional changes in onion