scholarly journals Blue Light Negatively Regulates Tolerance to Phosphate Deficiency in Arabidopsis

2017 ◽  
Author(s):  
Chuan-Ming Yeh ◽  
Koichi Kobayashi ◽  
Sho Fujii ◽  
Hidehiro Fukaki ◽  
Nobutaka Mitsuda ◽  
...  
Keyword(s):  
Blue Light ◽  
Lateral Roots ◽  
Primary Root ◽  
Utilization Efficiency ◽  
Phosphate Deficiency ◽  
Light Responses ◽  
Expression Of Genes ◽  
Pi Starvation ◽  
Pi Deficiency ◽  
Primary Root Length

AbstractPlants have evolved mechanisms to improve utilization efficiency or acquisition of inorganic phosphate (Pi) in response to Pi deficiency, such as altering root architecture, secreting acid phosphatases, and activating the expression of genes related to Pi uptake and recycling. Although many genes responsive to Pi starvation have been identified, transcription factors that affect tolerance to Pi deficiency have not been well characterized. We show here that defect in the ELONGATED HYPOCOTYL 5 (HY5) transcription factor gene results in tolerance to Pi deficiency in Arabidopsis. The primary root length of hy5 was only slightly inhibited under Pi deficient condition and its fresh weight was significantly higher than that of wild type. The Pi deficiency-tolerant phenotype of hy5 was similarly observed when grown on the medium without Pi. In addition, a double mutant, hy5slr1, without lateral roots also showed tolerance to phosphate deficiency, indicating that the tolerance of hy5 does not result from increase of external Pi uptake and may be related to internal Pi utilization or recycling. Moreover, we found that blue light negatively regulates tolerance to Pi-deficiency and that hy5 exhibits tolerance to Pi deficiency due to blockage of blue-light responses. Collectively, this study points out light quality may play an important role in the regulation of internal Pi recycling and utilization efficiency. Also, it may contribute to reducing Pi fertilizer requirements in plants through a proper illumination.

scholarly journals Effects of Phosphate Shortage on Root Growth and Hormone Content of Barley Depend on Capacity of the Roots to Accumulate ABA

Plants ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1722
Author(s):  
Lidiya Vysotskaya ◽  
Guzel Akhiyarova ◽  
Arina Feoktistova ◽  
Zarina Akhtyamova ◽  
Alla Korobova ◽  
...  
Keyword(s):  
Root Growth ◽  
Lateral Roots ◽  
Primary Root ◽  
Growth Responses ◽  
Root Tips ◽  
P Deficiency ◽  
Root Branching ◽  
Auxin Concentration ◽  
Shoot Mass ◽  
Primary Root Length

Although changes in root architecture in response to the environment can optimize mineral and water nutrient uptake, mechanisms regulating these changes are not well-understood. We investigated whether P deprivation effects on root development are mediated by abscisic acid (ABA) and its interactions with other hormones. The ABA-deficient barley mutant Az34 and its wild-type (WT) were grown in P-deprived and P-replete conditions, and hormones were measured in whole roots and root tips. Although P deprivation decreased growth in shoot mass similarly in both genotypes, only the WT increased primary root length and number of lateral roots. The effect was accompanied by ABA accumulation in root tips, a response not seen in Az34. Increased ABA in P-deprived WT was accompanied by decreased concentrations of cytokinin, an inhibitor of root extension. Furthermore, P-deficiency in the WT increased auxin concentration in whole root systems in association with increased root branching. In the ABA-deficient mutant, P-starvation failed to stimulate root elongation or promote branching, and there was no decline in cytokinin and no increase in auxin. The results demonstrate ABA’s ability to mediate in root growth responses to P starvation in barley, an effect linked to its effects on cytokinin and auxin concentrations.

GERMINATION, GROWTH AND DEVELOPMENT OF COMMON MILKWEED

1978 ◽  
Vol 58 (2) ◽  
pp. 493-498 ◽  
Author(s):  
PRASANTA C. BHOWMIK
Keyword(s):  
Lateral Roots ◽  
Seedling Emergence ◽  
Primary Root ◽  
Germination Percentage ◽  
Asclepias Syriaca ◽  
Seed Collection ◽  
Primary Roots ◽  
Number Of Leaves ◽  
Primary Root Length ◽  
Storage Temperatures

Germination percentage of common milkweed (Asclepias syriaca L.) seeds was low 1 mo after seed collection. Seed dormancy decreased with time at storage temperatures of −12°, 5° or 21 °C. After 11 months of storage, seeds stored at 21 °C had 15–18% higher germination compared to the seeds stored at −12° and 5 °C. The best seedling emergence was obtained at a temperature of 27 °C when seeds were planted at a depth of 0.5 or 1 cm. Seedling emergence was better in muck or sandy soil than in clay soil. Seedlings developed slowly up to 30 days after emergence at 15 °C under an 8-, 12- or 16-h photoperiod. High temperatures (27 °C) stimulated seedling growth under each photoperiod. Taller seedlings with more leaves, longer primary roots, more lateral roots and adventitious root buds grew at 27 °C as compared to 15° or 21 °C. Increasing the photoperiod from 8 to 16 h increased plant height and number of leaves but not primary root length.

scholarly journals Adaptation of the symbiotic Mesorhizobium–chickpea relationship to phosphate deficiency relies on reprogramming of whole-plant metabolism

2016 ◽  
Vol 113 (32) ◽  
pp. E4610-E4619 ◽  
Author(s):  
Maryam Nasr Esfahani ◽  
Miyako Kusano ◽  
Kien Huu Nguyen ◽  
Yasuko Watanabe ◽  
Chien Van Ha ◽  
...  
Keyword(s):  
Feedback Inhibition ◽  
Growth Parameters ◽  
Phosphate Deficiency ◽  
Plant Metabolism ◽  
Symbiotic Efficiency ◽  
Alternative Pathways ◽  
Enhanced Production ◽  
Whole Plant ◽  
Pi Starvation ◽  
Pi Deficiency

Low inorganic phosphate (Pi) availability is a major constraint for efficient nitrogen fixation in legumes, including chickpea. To elucidate the mechanisms involved in nodule acclimation to low Pi availability, two Mesorhizobium–chickpea associations exhibiting differential symbiotic performances, Mesorhizobium ciceri CP-31 (McCP-31)–chickpea and Mesorhizobium mediterranum SWRI9 (MmSWRI9)–chickpea, were comprehensively studied under both control and low Pi conditions. MmSWRI9–chickpea showed a lower symbiotic efficiency under low Pi availability than McCP-31–chickpea as evidenced by reduced growth parameters and down-regulation of nifD and nifK. These differences can be attributed to decline in Pi level in MmSWRI9-induced nodules under low Pi stress, which coincided with up-regulation of several key Pi starvation-responsive genes, and accumulation of asparagine in nodules and the levels of identified amino acids in Pi-deficient leaves of MmSWRI9-inoculated plants exceeding the shoot nitrogen requirement during Pi starvation, indicative of nitrogen feedback inhibition. Conversely, Pi levels increased in nodules of Pi-stressed McCP-31–inoculated plants, because these plants evolved various metabolic and biochemical strategies to maintain nodular Pi homeostasis under Pi deficiency. These adaptations involve the activation of alternative pathways of carbon metabolism, enhanced production and exudation of organic acids from roots into the rhizosphere, and the ability to protect nodule metabolism against Pi deficiency-induced oxidative stress. Collectively, the adaptation of symbiotic efficiency under Pi deficiency resulted from highly coordinated processes with an extensive reprogramming of whole-plant metabolism. The findings of this study will enable us to design effective breeding and genetic engineering strategies to enhance symbiotic efficiency in legume crops.

scholarly journals Solanum lycopersicum Seedlings. Metabolic Responses Induced by the Alkamide Affinin

Metabolites ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 143
Author(s):  
Tonatiu Campos-García ◽  
Jorge Molina-Torres
Keyword(s):  
Metabolic Pathways ◽  
Lateral Roots ◽  
Primary Root ◽  
Mitochondrial Electron Transport Chain ◽  
Metabolomic Analysis ◽  
Tomato Seedlings ◽  
Relieve Pain ◽  
Transport Chain ◽  
Primary Root Length

Alkamides have been observed to interact in different ways in several superior organisms and have been used in traditional medicine in many countries e.g., to relieve pain. Previous studies showed that affinin when applied to other plant species induces prominent changes in the root architecture and induces transcriptional adjustments; however, little is known about the metabolic pathways recruited by plants in response to alkamides. Previous published work with Arabidopsis seedlings treated in vitro with affinin at 50 µM significantly reduced primary root length. In tomato seedlings, that concentration did not reduce root growth but increase the number and length of lateral roots. Non-targeted metabolomic analysis by Gas Chromatography couplet to Mass Spectrometry (GC/EIMS) showed that, in tomato seedlings, affinin increased the accumulation of several metabolites leading to an enrichment of several metabolic pathways. Affinin at 100 µM alters the accumulation of metabolites such as organic acids, amino acids, sugars, and fatty acids. Finally, our results showed a response possibly associated with nitrogen, GABA shunt and serine pathways, in addition to a possible alteration in the mitochondrial electron transport chain (ETC), interesting topics to understand the molecular and metabolic mechanisms in response to alkamide in plants.

scholarly journals Genotypic variability of root and shoot traits of bread wheat (Triticum aestivum L.) at seedling stage

Genetika ◽  
2021 ◽  
Vol 53 (2) ◽  
pp. 687-702
Author(s):  
Milica Blazic ◽  
Dejan Dodig ◽  
Vesna Kandic ◽  
Dragoslav Djokic ◽  
Tomislav Zivanovic
Keyword(s):  
Bread Wheat ◽  
Root Length ◽  
Lateral Roots ◽  
Primary Root ◽  
Dry Weight ◽  
Triticum Aestivum L ◽  
Stem Length ◽  
Total Length ◽  
Seminal Roots ◽  
Primary Root Length

The evaluation of the embryonic root and stem of bread wheat (Triticum aestivum L.) in the early stage of development (seedling stage) can be a powerful tool in wheat breeding aimed at obtaining progenies with a greater early vigour. It is revealed that genotypes with faster early vigour have produced higher biomass and grain yield. In this study, the evaluation of traits of the embryonic root and the embryonic stem of 101 bread wheat genotypes was preformed at the 10-day old seedlings. The following eight morphological traits of roots and stems were analysed: primary root length, branching interval, the number of roots, total length of lateral roots, angle of seminal roots, stem length, root dry weight and the stem dry weight. Analysed lateral roots included seminal roots. The greatest, i.e. the smallest variability of observed traits was detected in the branching interval, i.e. the stem length, respectively. The highest positive correlation was determined between the primary root length and the total length of lateral roots. The cluster analysis, based on observed traits, shows that genotypes were clearly divided into two main clusters, A and B. The two clusters essentially differed from each other in the values of the following traits: primary root length, total length of lateral roots, root dry weight, stem dry weight and the stem length. Genotypes with shorter primary and lateral roots, lower root and stem dry weight and a shorter stem were grouped in the cluster B. On the other hand, the cluster A encompassed genotypes with values of these traits above or around the average. The values of the remaining analysed traits: the angle of seminal roots, the number of lateral roots and the branching interval varied greatly between obtained clusters. The cluster analysis showed the homogeneity of genotypes originating from Serbia and the region; their values of the root and stem length and weight were mostly around and below the average. However, the values of the angle of seminal roots, number of lateral roots and the branching interval were above average.

scholarly journals OsPDR2 Mediates the Regulation on the Development Response and Maintenance of Pi Homeostasis in Rice

2019 ◽  
Author(s):  
Yue Cao ◽  
Ajay Jain ◽  
Hao Ai ◽  
Xiuli Liu ◽  
Xiaowen Wang ◽  
...  
Keyword(s):  
Growth And Development ◽  
Reverse Genetics ◽  
Isotope Labeling ◽  
Primary Root ◽  
Reproductive Traits ◽  
Phosphate Deficiency ◽  
Relative Expression ◽  
Pi Homeostasis ◽  
Pi Deficiency

Abstract Background: Phosphate (Pi), is the least accessible macronutrient in many natural and agricultural ecosystems and its low availability often limits plant growth and productivity. In Arabidopsis thaliana (Arabidopsis), Phosphate Deficiency Response2 (AtPDR2), interacts genetically with Low Phosphate Root1 (AtLPR1) in the endoplasmic reticulum (ER), play a key role in Pi deficiency-mediated inhibition of the primary root growth and remodeling of the root system architecture (RSA). However, the role of OsPDR2, the homolog of AtPDR2, either in roots response to Pi deficiency and/or in growth and development has not been elucidated as yet. Results: Therefore, we investigated the spatiotemporal effects and the availability of Pi on the relative expression levels of OsPDR2 by employing qRT-PCR. OsPDR2 showed variable levels of relative expression pattern in vegetative and/or reproductive tissues analyzed at different stages of growth and development (5-17 weeks). Transient expression analysis revealed its subcellular localization to the ER. Further, the reverse genetics approach was employed for determining the function of OsPDR2 by RNAi-mediated suppression. Three independently generated RNAi lines (Ri2, Ri9, and Ri18) were compared with the wild-type (WT) for various vegetative and reproductive traits. The study revealed significant inhibitory effects of RNAi-mediated suppression of OsPDR2 on the root and male reproductive traits, and yield. Moreover, 32P isotope labeling and split-root experiments under different Pi regime with RNAi lines and the WT revealed the role of OsPDR2 in the maintenance of Pi homeostasis. Conclusions: The results from this study revealed the key role of OsPDR2 in the growth and development of rice and maintenance of phosphate homeostasis.

scholarly journals The Overexpression of NUC Promotes Development and Increases Resistance to Nitrogen Deficiency in Arabidopsis thaliana

2021 ◽  
Vol 22 (21) ◽  
pp. 11413
Author(s):  
Jing Ling ◽  
Xing Huang ◽  
Yanxia Jia ◽  
Weiqi Li ◽  
Xudong Zhang
Keyword(s):  
Binding Sites ◽  
Lateral Roots ◽  
Nitrogen Deficiency ◽  
Primary Root ◽  
Regulatory Function ◽  
Promoter Regions ◽  
Juvenile Stages ◽  
N Deficiency ◽  
Primary Root Length ◽  
Insight Into

NUTCRACKER (NUC) is a transcription factor expressed in multiple tissues, but little is known about its physiological roles. In this study, we explored the physiological function of NUC with the Arabidopsis knockout, rescue, and overexpression lines. We found that NUC overexpression promoted development at the germination, seedling, and juvenile stages. NUC overexpression increased resistance to nitrogen (N) deficiency stress by increasing the chlorophyll content, suppressing anthocyanin accumulation, and increasing the biomass under N deficiency. In contrast, the absence of NUC did not affect such characteristics. N deficiency significantly increased the expression of NUC in leaves but did not affect the expression of NUC in roots. The overexpression of NUC promoted primary root length under both normal and N deficiency conditions. Furthermore, we found that the N-responsive and lateral-root-related genes TGA1 and NRT2.4 had NUC-binding sites in their promoter regions and that their expression was upregulated by NUC under N deficiency. The overexpression of the NUC increased the number and length of the lateral roots under N deficiency through inducible promotion. Multiple lines of investigation suggest that the regulatory function of the NUC could be bypassed through its redundant MAGPIE (MGP) when the NUC is absent. Our findings provide novel insight into NUC’s functions and will assist efforts to improve plants’ development and resistance to nutrient stresses.

scholarly journals Evaluations and Correlated Responses for Resistance to Chloramben Herbicide in Cucumber

HortScience ◽  
1991 ◽  
Vol 26 (7) ◽  
pp. 905-908
Author(s):  
Jack E. Staub ◽  
Larry D. Knerr ◽  
Leslie A. Weston
Keyword(s):  
Lateral Roots ◽  
Primary Root ◽  
Germplasm Collection ◽  
Percentage Germination ◽  
Correlated Responses ◽  
Genetic Response ◽  
Family Selection ◽  
Hypocotyl Length ◽  
Plant Introductions ◽  
Primary Root Length

The U.S. cucumber germplasm collection (753 accessions) and U.S. adapted processing cucumber (Cucumis sativus L.) inbreds and hybrids were surveyed for response to 6.7 kg ae/ha of chloramben. Nine plant introductions (PI 165952, 173892, 179676, 275411, 277741, 279464, 279465, 436609, and 482464) were classified as tolerant to chloramben, based on percentage and rate of field emergence and seedling vigor. All adapted strains evaluated were susceptible to chloramben injury. The chloramben-tolerant accessions (C0) were subjected to two cycles of recurrent half-sib family selection that resulted in 11 C2 families. These families, a susceptible adapted line (WI 2870), and the resistant PI 436609 were evaluated in the field (6.7 kg ae/ha) and laboratory (0.0, 0.01, and 0.0001 M) for response to chloramben challenge. Significant (P = 0.05) differences between families were observed for percentage emergence and phytotoxicity ratings. Correlations between emergence and phytotoxicity ratings at two dates were low (r2 = -0.32 and – 0.05). Significant (P = 0.05) interfamily differences were also recorded for percentage germination, hypocotyl length, primary root length, and number of lateral roots in the laboratory. Correlated responses between these growth variables were high (r2 = 0.78 to 0.84), but correlations between field and laboratory observations were low (r2 = -0.31 to 0.24). We hypothesize that the genetic response to chloramben challenge under laboratory conditions depends on the concentration of the chemical administered. Chemical name used: 3-amino-2, 5-dichlorobenzoic acid (chloramben).

scholarly journals Transcription Factor WRKY33 Mediates the Phosphate Deficiency-Induced Remodeling of Root Architecture by Modulating Iron Homeostasis in Arabidopsis Roots

2021 ◽  
Vol 22 (17) ◽  
pp. 9275
Author(s):  
Nuo Shen ◽  
Sifan Hou ◽  
Guoqing Tu ◽  
Wenzhi Lan ◽  
Yanping Jing
Keyword(s):  
Transcription Factor ◽  
Transcription Factors ◽  
Root Growth ◽  
Root Architecture ◽  
Iron Homeostasis ◽  
Primary Root ◽  
Negative Regulator ◽  
Phosphate Deficiency ◽  
Root Tips ◽  
Pi Deficiency

The remodeling of root architecture is regarded as a major development to improve the plant’s adaptivity to phosphate (Pi)-deficient conditions. The WRKY transcription factors family has been reported to regulate the Pi-deficiency-induced systemic responses by affecting Pi absorption or transportation. Whether these transcription factors act as a regulator to mediate the Pi-deficiency-induced remodeling of root architecture, a typical local response, is still unclear. Here, we identified an Arabidopsis transcription factor, WRKY33, that acted as a negative regulator to mediate the Pi-deficiency-induced remodeling of root architecture. The disruption of WRKY33 in wrky33-2 mutant increased the plant’s low Pi sensitivity by further inhibiting the primary root growth and promoting the formation of root hair. Furthermore, we revealed that WRKY33 negatively regulated the remodeling of root architecture by controlling the transcriptional expression of ALMT1 under Pi-deficient conditions, which further mediated the Fe3+ accumulation in root tips to inhibit the root growth. In conclusion, this study demonstrates a previously unrecognized signaling crosstalk between WRKY33 and the ALMT1-mediated malate transport system to regulate the Pi deficiency responses.

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