scholarly journals Phosphorus and nitrogen interaction: loss of QC identity in response to P or N limitation is antecipated in pdr23 mutant

2011 ◽  
Vol 23 (3) ◽  
pp. 219-229 ◽  
Author(s):  
Cibele T. Costa ◽  
Mércio L. Strieder ◽  
Stephen Abel ◽  
Carla A. Delatorre
Keyword(s):  
Nucleic Acids ◽  
Lateral Roots ◽  
Adaptive Strategy ◽  
Quiescent Center ◽  
Wild Type ◽  
Short Root ◽  
Alternative Source ◽  
Low Phosphorus ◽  
Determinate Growth ◽  
Arabidopsis Mutant

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.

scholarly journals Uncoupling Salicylic Acid-Dependent Cell Death and Defense-Related Responses From Disease Resistance in the Arabidopsis Mutant acd5

Genetics ◽  
2000 ◽  
Vol 156 (1) ◽  
pp. 341-350
Author(s):  
Jean T Greenberg ◽  
F Paul Silverman ◽  
Hua Liang
Keyword(s):  
Cell Death ◽  
Salicylic Acid ◽  
Disease Resistance ◽  
Pseudomonas Syringae ◽  
Higher Plants ◽  
Ethylene Signaling ◽  
Symptom Development ◽  
Wild Type ◽  
Dependent Cell ◽  
Arabidopsis Mutant

Abstract Salicylic acid (SA) is required for resistance to many diseases in higher plants. SA-dependent cell death and defense-related responses have been correlated with disease resistance. The accelerated cell death 5 mutant of Arabidopsis provides additional genetic evidence that SA regulates cell death and defense-related responses. However, in acd5, these events are uncoupled from disease resistance. acd5 plants are more susceptible to Pseudomonas syringae early in development and show spontaneous SA accumulation, cell death, and defense-related markers later in development. In acd5 plants, cell death and defense-related responses are SA dependent but they do not confer disease resistance. Double mutants with acd5 and nonexpressor of PR1, in which SA signaling is partially blocked, show greatly attenuated cell death, indicating a role for NPR1 in controlling cell death. The hormone ethylene potentiates the effects of SA and is important for disease symptom development in Arabidopsis. Double mutants of acd5 and ethylene insensitive 2, in which ethylene signaling is blocked, show decreased cell death, supporting a role for ethylene in cell death control. We propose that acd5 plants mimic P. syringae-infected wild-type plants and that both SA and ethylene are normally involved in regulating cell death during some susceptible pathogen infections.

scholarly journals Estimating the importance of maize root hairs in low phosphorus conditions and under drought

2019 ◽  
Vol 124 (6) ◽  
pp. 961-968 ◽  
Author(s):  
Florian Klamer ◽  
Florian Vogel ◽  
Xuelian Li ◽  
Hinrich Bremer ◽  
Günter Neumann ◽  
...  
Keyword(s):  
Root Hairs ◽  
Specific Root Length ◽  
P Uptake ◽  
Alkaline Soil ◽  
Secondary Effects ◽  
Short Root ◽  
P Deficiency ◽  
P Content ◽  
Low Phosphorus ◽  
P Supply

Abstract Background and Aims Root hairs are single-cell extensions of the epidermis that face into the soil and increase the root–soil contact surface. Root hairs enlarge the rhizosphere radially and are very important for taking up water and sparingly soluble nutrients, such as the poorly soil-mobile phosphate. In order to quantify the importance of root hairs for maize, a mutant and the corresponding wild type were compared. Methods The rth2 maize mutant with very short root hairs was assayed for growth and phosphorus (P) acquisition in a slightly alkaline soil with low P and limited water supply in the absence of mycorrhization and with ample P supply. Key Results Root and shoot growth was additively impaired under P deficiency and drought. Internal P concentrations declined with reduced water and P supply, whereas micronutrients (iron, zinc) were little affected. The very short root hairs in rth2 did not affect internal P concentrations, but the P content of juvenile plants was halved under combined stress. The rth2 plants had more fine roots and increased specific root length, but P mobilization traits (root organic carbon and phosphatase exudation) differed little. Conclusions The results confirm the importance of root hairs for maize P uptake and content, but not for internal P concentrations. Furthermore, the performance of root hair mutants may be biased by secondary effects, such as altered root growth.

scholarly journals A fern WUSCHEL-RELATED HOMEOBOX gene functions in both gametophyte and sporophyte generations

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Christopher E. Youngstrom ◽  
Lander F. Geadelmann ◽  
Erin E. Irish ◽  
Chi-Lien Cheng
Keyword(s):  
Stem Cells ◽  
Lateral Roots ◽  
Homeobox Gene ◽  
Genetic Networks ◽  
Land Plants ◽  
Seed Plants ◽  
Wild Type ◽  
Cell Fates ◽  
Cell Divisions ◽  
Gene Functions

Abstract Background Post-embryonic growth of land plants originates from meristems. Genetic networks in meristems maintain the stem cells and direct acquisition of cell fates. WUSCHEL-RELATED HOMEOBOX (WOX) transcription factors involved in meristem networks have only been functionally characterized in two evolutionarily distant taxa, mosses and seed plants. This report characterizes a WOX gene in a fern, which is located phylogenetically between the two taxa. Results CrWOXB transcripts were detected in proliferating tissues, including gametophyte and sporophyte meristems of Ceratopteris richardii. In addition, CrWOXB is expressed in archegonia but not the antheridia of gametophytes. Suppression of CrWOXB expression in wild-type RN3 plants by RNAi produced abnormal morphologies of gametophytes and sporophytes. The gametophytes of RNAi lines produced fewer cells, and fewer female gametes compared to wild-type. In the sporophyte generation, RNAi lines produced fewer leaves, pinnae, roots and lateral roots compared to wild-type sporophytes. Conclusions Our results suggest that CrWOXB functions to promote cell divisions and organ development in the gametophyte and sporophyte generations, respectively. CrWOXB is the first intermediate-clade WOX gene shown to function in both generations in land plants.

scholarly journals Effects of Jasmonate on Ethylene Function during the Development of Tomato Stamens

Plants ◽  
2019 ◽  
Vol 8 (8) ◽  
pp. 277 ◽  
Author(s):  
Ramona Schubert ◽  
Stephan Grunewald ◽  
Lea von Sivers ◽  
Bettina Hause
Keyword(s):  
Water Content ◽  
Minor Role ◽  
Wild Type ◽  
Stamen Development ◽  
Hormone Levels ◽  
Pollen Release ◽  
Arabidopsis Mutant ◽  
Ethylene Function ◽  
Pollen Vitality

The phenotype of the tomato mutant jasmonate-insensitive1-1 (jai1-1) mutated in the JA-Ile co-receptor COI1 demonstrates JA function in flower development, since it is female-sterile. In addition, jai1-1 exhibits a premature anther dehydration and pollen release, being in contrast to a delayed anther dehiscence in the JA-insensitive Arabidopsis mutant coi1-1. The double mutant jai1-1 Never ripe (jai1-1 Nr), which is in addition insensitive to ethylene (ET), showed a rescue of the jai1-1 phenotype regarding pollen release. This suggests that JA inhibits a premature rise in ET to prevent premature stamen desiccation. To elucidate the interplay of JA and ET in more detail, stamen development in jai1-1 Nr was compared to wild type, jai1-1 and Nr regarding water content, pollen vitality, hormone levels, and accumulation of phenylpropanoids and transcripts encoding known JA- and ET-regulated genes. For the latter, RT-qPCR based on nanofluidic arrays was employed. The data showed that additional prominent phenotypic features of jai1-1, such as diminished water content and pollen vitality, and accumulation of phenylpropanoids were at least partially rescued by the ET-insensitivity. Hormone levels and accumulation of transcripts were not affected. The data revealed that strictly JA-regulated processes cannot be rescued by ET-insensitivity, thereby emphasizing a rather minor role of ET in JA-regulated stamen development.

scholarly journals Morpho-anatomical features of underground systems in six Asteraceae species from the Brazilian Cerrado

2011 ◽  
Vol 83 (3) ◽  
pp. 981-992 ◽  
Author(s):  
Beatriz Appezzato-da-Glória ◽  
Graziela Cury
Keyword(s):  
Environmental Conditions ◽  
Lateral Roots ◽  
Adaptive Strategy ◽  
Herbaceous Species ◽  
Bud Bank ◽  
Brazilian Cerrado ◽  
Neotropical Savanna ◽  
Anatomical Features ◽  
Paulo State ◽  
Vegetation Regeneration

In the Brazilian Cerrado (neotropical savanna), the development of bud-bearing underground systems as adaptive structures to fire and dry periods can comprise an important source of buds for this ecosystem, as already demonstrated in the Brazilian Campos grasslands and North American prairies. Asteraceae species from both woody and herbaceous strata have subterranean organs that accumulate carbohydrates, reinforcing the adaptive strategy of these plants to different environmental conditions. This study aims to analyse the morpho-anatomy of underground systems of six species of Asteraceae (Mikania cordifolia L.f. Willd., Mikania sessilifolia DC, Trixis nobilis (Vell.) Katinas, Pterocaulon alopecuroides (Lam.) DC., Vernonia elegans Gardner and Vernonia megapotamica Spreng.), to describe these structures and to verify the occurrence and origin of shoot buds, and to analyse the presence of reserve substances. Individuals sampled in Cerrado areas in São Paulo State showed thick underground bud-bearing organs, with adventitious or lateral roots and presence of fructans. Xylopodium was found in all studied species, except for Trixis nobilis, which had stem tuber. The presence of fructans as reserve, and the capacity of structures in the formation of buds indicate the potential of herbaceous species of Asteraceae in forming a viable bud bank for vegetation regeneration in the Brazilian Cerrado.

The contribution of lateral rooting to phosphorus acquisition efficiency in maize (Zea mays) seedlings

2004 ◽  
Vol 31 (10) ◽  
pp. 949 ◽  
Author(s):  
Jinming Zhu ◽  
Jonathan P. Lynch
Keyword(s):  
Growth Rate ◽  
Lateral Root ◽  
Root Respiration ◽  
Lateral Roots ◽  
Biomass Accumulation ◽  
Phosphorus Availability ◽  
Phosphorus Acquisition ◽  
Relative Growth ◽  
Phosphorus Stress ◽  
Low Phosphorus

Low soil phosphorus availability is a primary constraint for plant growth in many terrestrial ecosystems. Lateral root initiation and elongation may play an important role in the uptake of immobile nutrients, such as phosphorus, by increasing soil exploration and phosphorus solubilisation. The overall objective of this study was to assess the value of lateral rooting for phosphorus acquisition through assessment of the ‘benefit’ of lateral rooting for phosphorus uptake and the ‘cost’ of lateral roots in terms of root respiration and phosphorus investment at low and high phosphorus availability. Five recombinant inbred lines (RILs) of maize derived from a cross between B73 and Mo17 with contrasting lateral rooting were grown in sand culture in a controlled environment. Genotypes with enhanced or sustained lateral rooting at low phosphorus availability had greater phosphorus acquisition, biomass accumulation, and relative growth rate (RGR) than genotypes with reduced lateral rooting at low phosphorus availability. The association of lateral root development and plant biomass accumulation under phosphorus stress was not caused by allometry. Genotypes varied in the phosphorus investment required for lateral root elongation, owing to genetic differences in specific root length (SRL, which was correlated with root diameter) and phosphorus concentration of lateral roots. Lateral root extension required less biomass and phosphorus investment than the extension of other root types. Relative growth rate was negatively correlated with specific root respiration, supporting the hypothesis that root carbon costs are an important aspect of adaptation to low phosphorus availability. Two distinct cost–benefit analyses, one with phosphorus acquisition rate as a benefit and root respiration as a cost, the other with plant phosphorus accumulation as a benefit and phosphorus allocation to lateral roots as a cost, both showed that lateral rooting was advantageous under conditions of low phosphorus availability. Our data suggest that enhanced lateral rooting under phosphorus stress may be harnessed as a useful trait for the selection and breeding of more phosphorus-efficient maize genotypes.

scholarly journals NABP1, a novel RORγ-regulated gene encoding a single-stranded nucleic-acid-binding protein

2006 ◽  
Vol 397 (1) ◽  
pp. 89-99 ◽  
Author(s):  
Hong Soon Kang ◽  
Ju Youn Beak ◽  
Yong-Sik Kim ◽  
Robert M. Petrovich ◽  
Jennifer B. Collins ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Nucleic Acids ◽  
Binding Protein ◽  
Size Exclusion ◽  
Binding Motif ◽  
Nucleic Acid Binding ◽  
Wild Type ◽  
Gene Encoding ◽  
Nucleic Acid Binding Protein ◽  
Acid Binding Protein

RORγ2 (retinoid-related orphan receptor γ2) plays a critical role in the regulation of thymopoiesis. Microarray analysis was performed in order to uncover differences in gene expression between thymocytes of wild-type and RORγ−/− mice. This analysis identified a novel gene encoding a 22 kDa protein, referred to as NABP1 (nucleic-acid-binding protein 1). This subsequently led to the identification of an additional protein, closely related to NABP1, designated NABP2. Both proteins contain an OB (oligonucleotide/oligosaccharide binding) motif at their N-terminus. This motif is highly conserved between the two proteins. NABP1 is highly expressed in the thymus of wild-type mice and is greatly suppressed in RORγ−/− mice. During thymopoiesis, NABP1 mRNA expression is restricted to CD4+CD8+ thymocytes, an expression pattern similar to that observed for RORγ2. These observations appear to suggest that NABP1 expression is regulated either directly or indirectly by RORγ2. Confocal microscopic analysis showed that the NABP1 protein localizes to the nucleus. Analysis of nuclear proteins by size-exclusion chromatography indicated that NABP1 is part of a high molecular-mass protein complex. Since the OB-fold is frequently involved in the recognition of nucleic acids, the interaction of NABP1 with various nucleic acids was examined. Our results demonstrate that NABP1 binds single-stranded nucleic acids, but not double-stranded DNA, suggesting that it functions as a single-stranded nucleic acid binding protein.

scholarly journals Shoot-derived miR2111 controls legume root and nodule development

2020 ◽  
Author(s):  
Mengbai Zhang ◽  
Huanan Su ◽  
Peter M. Gresshoff ◽  
Brett J. Ferguson
Keyword(s):  
Lateral Root ◽  
Lateral Roots ◽  
Ectopic Expression ◽  
Root System Architecture ◽  
Negative Regulator ◽  
Nodule Development ◽  
Wild Type ◽  
Root Branching ◽  
Autoregulation Of Nodulation ◽  
Cle Peptide

AbstractLegumes control their nodule numbers through the Autoregulation Of Nodulation (AON). Rhizobia infection stimulates the production of root-derived CLE peptide hormones that are translocated to the shoot where they regulate a new signal. We used soybean to demonstrate that this shoot-derived signal is miR2111, which is transported via phloem to the root where it targets transcripts of Too Much Love (TML), a negative regulator of nodulation. Shoot perception of rhizobia-induced CLE peptides suppresses miR2111 expression, resulting in TML accumulation in roots and subsequent inhibition of nodule organogenesis. Feeding synthetic mature miR2111 via the petiole increased nodule numbers per plant. Likewise, elevating miR2111 availability by over-expression promoted nodulation, while target mimicry of TML induced the opposite effect on nodule development in wild-type plants and alleviated the supernodulating and stunted root growth phenotypes of AON-defective mutants. Additionally, in non-nodulating wild-type plants, ectopic expression of miR2111 significantly enhanced lateral root emergence with a decrease in lateral root length and average root diameter. In contrast, hairy roots constitutively expressing the target mimic construct exhibited reduced lateral root density. Overall, these findings demonstrate that miR2111 is both the critical shoot-to-root factor that positively regulates root nodule development, and also acts to shape root system architecture via orchestrating the degree of root branching, as well as the length and thickness of lateral roots.

scholarly journals An R2R3-MYB Transcription Factor PgFLP Directly Activates PgPIN10 to Regulate the GSA of Adventitious Root in Pomegranate

2020 ◽  
Author(s):  
Zenghui Wang ◽  
Jialin Li ◽  
Xuemei Yang ◽  
Haixia Tang ◽  
Lijuan Feng ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Adventitious Root ◽  
Molecular Mechanisms ◽  
Lateral Roots ◽  
Myb Transcription Factor ◽  
Wild Type ◽  
Set Point ◽  
Root Gravitropism ◽  
Gravity Signal ◽  
R2r3 Myb

Abstract Background: The self-rooted seedling is widely used in pomegranate planting industry currently; However, the root system of self-rooted seedling is shallow and poor cold resistance. Therefore, the study of the molecular mechanisms of pomegranate adventitious root gravitropism is very important for developing deep-rooted pomegranate cultivars.Results: We report the pomegranate FOUR LIPS (PgFLP) that play an key role in regulating the gravitropic set-point angle of pomegranate adventitious root in response to gravity signal. In our study, PgFLP directly regulates the transcriptional expression of PgPIN10 by binding to its promoter, thus regulating the GSA of adventitious root in pomegranate. Additionally, the 35S::PgFLP show stronger gravitational response than wild-type, leading to a smaller GSA in Arabidopsis lateral roots, indicating that PgFLP participates in regulating the GSA of adventitious root via PgPIN10 in pomegranate. Conclusion: Our results confirm that the transcriptional regulation of PgPIN10 by R2R3-MYB transcription factor PgFLP in setting the gravitropic set-point angle of pomegranate adventitious root in response to gravity signal.

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