TY - JOUR ID - 2195 TI - Ambient temperature and genotype differentially affect developmental and phenotypic plasticity in Arabidopsis thaliana JO - BMC Plant Biol PY - 2017 SP - 114 AU - Ibañez, C. AU - Poeschl, Y. AU - Peterson, T. AU - Bellstädt, J. AU - Denk, K. AU - Gogol-Döring, A. AU - Quint, M. AU - Delker, C. VL - 17 UR - https://dx.doi.org/10.1186/s12870-017-1068-5 DO - 10.1186/s12870-017-1068-5 AB - BackgroundGlobal increase in ambient temperatures constitute a significant challenge to wild and cultivated plant species. Forward genetic analyses of individual temperature-responsive traits have resulted in the identification of several signaling and response components. However, a comprehensive knowledge about temperature sensitivity of different developmental stages and the contribution of natural variation is still scarce and fragmented at best.ResultsHere, we systematically analyze thermomorphogenesis throughout a complete life cycle in ten natural Arabidopsis thaliana accessions grown under long day conditions in four different temperatures ranging from 16 to 28 °C. We used Q10, GxE, phenotypic divergence and correlation analyses to assess temperature sensitivity and genotype effects of more than 30 morphometric and developmental traits representing five phenotype classes. We found that genotype and temperature differentially affected plant growth and development with variing strengths. Furthermore, overall correlations among phenotypic temperature responses was relatively low which seems to be caused by differential capacities for temperature adaptations of individual accessions.ConclusionGenotype-specific temperature responses may be attractive targets for future forward genetic approaches and accession-specific thermomorphogenesis maps may aid the assessment of functional relevance of known and novel regulatory components. A2 - C1 - Molecular Signal Processing ER - TY - JOUR ID - 1894 TI - Comparative expression profiling reveals a role of the root apoplast in local phosphate response JO - BMC Plant Biol PY - 2016 SP - 106 AU - Hoehenwarter, W. AU - Mönchgesang, S. AU - Neumann, S. AU - Majovsky, P. AU - Abel, S. AU - Müller, J. VL - 16 UR - https://dx.doi.org/10.1186/s12870-016-0790-8 DO - 10.1186/s12870-016-0790-8 AB - BackgroundPlant adaptation to limited phosphate availability comprises a wide range of responses to conserve and remobilize internal phosphate sources and to enhance phosphate acquisition. Vigorous restructuring of root system architecture provides a developmental strategy for topsoil exploration and phosphate scavenging. Changes in external phosphate availability are locally sensed at root tips and adjust root growth by modulating cell expansion and cell division. The functionally interacting Arabidopsis genes, LOW PHOSPHATE RESPONSE 1 and 2 (LPR1/LPR2) and PHOSPHATE DEFICIENCY RESPONSE 2 (PDR2), are key components of root phosphate sensing. We recently demonstrated that the LOW PHOSPHATE RESPONSE 1 - PHOSPHATE DEFICIENCY RESPONSE 2 (LPR1-PDR2) module mediates apoplastic deposition of ferric iron (Fe3+) in the growing root tip during phosphate limitation. Iron deposition coincides with sites of reactive oxygen species generation and triggers cell wall thickening and callose accumulation, which interfere with cell-to-cell communication and inhibit root growth.ResultsWe took advantage of the opposite phosphate-conditional root phenotype of the phosphate deficiency response 2 mutant (hypersensitive) and low phosphate response 1 and 2 double mutant (insensitive) to investigate the phosphate dependent regulation of gene and protein expression in roots using genome-wide transcriptome and proteome analysis. We observed an overrepresentation of genes and proteins that are involved in the regulation of iron homeostasis, cell wall remodeling and reactive oxygen species formation, and we highlight a number of candidate genes with a potential function in root adaptation to limited phosphate availability. Our experiments reveal that FERRIC REDUCTASE DEFECTIVE 3 mediated, apoplastic iron redistribution, but not intracellular iron uptake and iron storage, triggers phosphate-dependent root growth modulation. We further highlight expressional changes of several cell wall-modifying enzymes and provide evidence for adjustment of the pectin network at sites of iron accumulation in the root.ConclusionOur study reveals new aspects of the elaborate interplay between phosphate starvation responses and changes in iron homeostasis. The results emphasize the importance of apoplastic iron redistribution to mediate phosphate-dependent root growth adjustment and suggest an important role for citrate in phosphate-dependent apoplastic iron transport. We further demonstrate that root growth modulation correlates with an altered expression of cell wall modifying enzymes and changes in the pectin network of the phosphate-deprived root tip, supporting the hypothesis that pectins are involved in iron binding and/or phosphate mobilization. A2 - C1 - Synergy Research Groups; Molecular Signal Processing ER - TY - JOUR ID - 1770 TI - Auxin-induced degradation dynamics set the pace for lateral root development JO - Development PY - 2015 SP - 1-5 AU - Guseman, J. M. AU - Hellmuth, A. AU - Lanctot, A. AU - Feldman, T. P. AU - Moss, B. L. AU - Klavins, E. AU - Calderón Villalobos, L. I. A. AU - Nemhauser, J. L. VL - 142 UR - http://dev.biologists.org/content/early/2015/01/29/dev.117234.abstract?sid=44c8748f-9cc2-4f71-93df-bfbc96e0a0c2 DO - 10.1242/dev.117234 AB - Auxin elicits diverse cell behaviors through a simple nuclear signaling pathway initiated by degradation of Aux/IAA co-repressors. Our previous work revealed that members of the large Arabidopsis Aux/IAA family exhibit a range of degradation rates in synthetic contexts. However, it remained an unresolved issue whether differences in Aux/IAA turnover rates played a significant role in plant responses to auxin. Here, we use the well-established model of lateral root development to directly test the hypothesis that the rate of auxin-induced Aux/IAA turnover sets the pace for auxin-regulated developmental events. We did this by generating transgenic plants expressing degradation rate variants of IAA14, a crucial determinant of lateral root initiation. Progression through the well-established stages of lateral root development was strongly correlated with the engineered rates of IAA14 turnover, leading to the conclusion that Aux/IAAs are auxin-initiated timers that synchronize developmental transitions A2 - C1 - Molecular Signal Processing ER - TY - JOUR ID - 1445 TI - Phosphorus and nitrogen interaction: loss of QC identity in response to P or N limitation is antecipated in pdr23 mutant JO - Braz J Plant Physiol PY - 2011 SP - 219-229 AU - Costa, C. T. AU - Strieder, M. L. AU - Abel, S. AU - Delatorre, C. A. VL - 23 UR - https://dx.doi.org/10.1590/S1677-04202011000300006 DO - 10.1590/S1677-04202011000300006 AB - Changes in root architecture are an important adaptive strategy used by plants in response to limited nutrient availability to increase the odds of acquiring them. The quiescent center (QC) plays an important role by altering the meristem activity causing differentiation and therefore, inducing a determinate growth program. The arabidopsis mutant pdr23 presents primary short root in the presence of nitrate and is inefficient in the use of nucleic acids as a source of phosphorus. In this study the effect of the pdr23 mutation on the QC maintenance under low phosphorus (P) and/or nitrogen is evaluated. QC identity is maintained in wild-type in the absence of nitrate and/or phosphate if nucleic acids can be used as an alternative source of these nutrients, but not in pdr23. The mutant is not able to use nucleic acids efficiently for substitute Pi, determinate growth is observed, similar to wild-type in the total absence of P. In the absence of N pdr23 loses the expression of QC identity marker earlier than wild-type, indicating that not only the response to P is altered, but also to N. The data suggest that the mutation affects a gene involved either in the crosstalk between these nutrients or in a pathway shared by both nutrients limitation response. Moreover loss of QC identity is also observed in wild-type in the absence of N at longer limitation. Less drastic symptoms are observed in lateral roots of both genotypes. A2 - C1 - Molecular Signal Processing ER - TY - JOUR ID - 1304 TI - Phosphate sensing in root development JO - Curr Opin Plant Biol PY - 2011 SP - 303-309 AU - Abel, S. VL - 14 UR - https://dx.doi.org/10.1016/j.pbi.2011.04.007 DO - 10.1016/j.pbi.2011.04.007 AB - Phosphate (Pi) and its anhydrides constitute major nodes in metabolism. Thus, plant performance depends directly on Pi nutrition. Inadequate Pi availability in the rhizosphere is a common challenge to plants, which activate metabolic and developmental responses to maximize Pi usage and acquisition. The sensory mechanisms that monitor environmental Pi and transmit the nutritional signal to adjust root development have increasingly come into focus. Recent transcriptomic analyses and genetic approaches have highlighted complex antagonistic interactions between external Pi and Fe bioavailability and have implicated the stem cell niche as a target of Pi sensing to regulate root meristem activity. A2 - C1 - Molecular Signal Processing ER - TY - JOUR ID - 831 TI - Isolation and characterization of the glutaminyl cyclases from Solanum tuberosum and Arabidopsis thaliana: implications for physiological functions JO - Biol. Chem PY - 2007 SP - 145-153 AU - Schilling, S. AU - Stenzel, I. AU - von Bohlen, A. AU - Wermann, M. AU - Schulz, K. AU - Demuth, H.-U. AU - Wasternack, C. VL - 388 UR - DO - 10.1515/BC.2007.016 AB - A2 - C1 - Molecular Signal Processing ER - TY - JOUR ID - 854 TI - Auxin signaling JO - Curr Opin Plant Biol PY - 2006 SP - 448-453 AU - Quint, M. AU - Gray, W.M. VL - 9 UR - DO - 10.1016/j.pbi.2006.07.006 AB - Auxin regulates a host of plant developmental and physiological processes, including embryogenesis, vascular differentiation, organogenesis, tropic growth, and root and shoot architecture. Genetic and biochemical studies carried out over the past decade have revealed that much of this regulation involves the SCFTIR1/AFB-mediated proteolysis of the Aux/IAA family of transcriptional regulators. With the recent finding that the TRANSPORT INHIBITOR RESPONSE1 (TIR1)/AUXIN SIGNALING F-BOX (AFB) proteins also function as auxin receptors, a potentially complete, and surprisingly simple, signaling pathway from perception to transcriptional response is now before us. However, understanding how this seemingly simple pathway controls the myriad of specific auxin responses remains a daunting challenge, and compelling evidence exists for SCFTIR1/AFB-independent auxin signaling pathways. A2 - C1 - Molecular Signal Processing ER - TY - JOUR ID - 1136 TI - Secretory ribonucleases from tomato (Lycopersicon esculentum cv. Mill.) JO - Meth Enzymol PY - 2001 SP - 351 - 368 AU - Abel, S. AU - Köck, M. VL - 341 UR - AB - A2 - C1 - Molecular Signal Processing ER -