A Foldable Chip Array for the Continuous Investigation of Seed Germination and the Subsequent Root Development of Seedlings

Seed germination and seedling root development are important indicators of plant development. This work designed and fabricated a foldable microfluidic chip array for conducting nondestructive and continuous evaluation of seed germination and subsequent seedling development in situ. Each plant chamber has two functional units: seed germination part and root-growth part. The root-growth parts are themselves connected to a single channel designed to provide a uniform culture medium for plant growth. The individual chips are connected into an array using elastic hinges that facilitate the folding and unfolding of the array to accommodate different viewing purposes. In the folded state, the seed germination chambers form a closely spaced array platform to facilitate the comparison of seed germination and plant development characteristics. Unfolding the array facilitates a clear examination of root development within the root-growth parts. The observation window of an individual chip facilitates either the direct examination of the developing seedling (e.g., stems and leaves) or the use of a microscope for examining microscale features (e.g., root tips and root hairs). The potential of the proposed foldable chip array as a new cultivation platform for botanic studies is demonstrated by examining the seed germination and seedling development of tobacco (Nicotiana tabacum) under different cultivation conditions.

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BrEXLB1, a Brassica rapa Expansin-Like B1 Gene Is Associated with Root Development, Drought Stress Response, and Seed Germination

Genes ◽

10.3390/genes11040404 ◽

2020 ◽

Vol 11 (4) ◽

pp. 404 ◽

Cited By ~ 2

Author(s):

Muthusamy Muthusamy ◽

Joo Yeol Kim ◽

Eun Kyung Yoon ◽

Jin A. Kim ◽

Soo In Lee

Keyword(s):

Abiotic Stress ◽

Drought Stress ◽

Stress Response ◽

Seed Germination ◽

Drought Tolerance ◽

Root Growth ◽

Brassica Rapa ◽

Root Development ◽

Clubroot Disease ◽

Qrt Pcr

Expansins are structural proteins prevalent in cell walls, participate in cell growth and stress responses by interacting with internal and external signals perceived by the genetic networks of plants. Herein, we investigated the Brassica rapa expansin-like B1 (BrEXLB1) interaction with phytohormones (IAA, ABA, Ethephon, CK, GA3, SA, and JA), genes (Bra001852, Bra001958, and Bra003006), biotic (Turnip mosaic Virus (TuMV), Pectobacterium carotovorum, clubroot disease), and abiotic stress (salt, oxidative, osmotic, and drought) conditions by either cDNA microarray or qRT-PCR assays. In addition, we also unraveled the potential role of BrEXLB1 in root growth, drought stress response, and seed germination in transgenic Arabidopsis and B. rapa lines. The qRT-PCR results displayed that BrEXLB1 expression was differentially influenced by hormones, and biotic and abiotic stress conditions; upregulated by IAA, ABA, SA, ethylene, drought, salt, osmotic, and oxidative conditions; and downregulated by clubroot disease, P. carotovorum, and TuMV infections. Among the tissues, prominent expression was observed in roots indicating the possible role in root growth. The root phenotyping followed by confocal imaging of root tips in Arabidopsis lines showed that BrEXLB1 overexpression increases the size of the root elongation zone and induce primary root growth. Conversely, it reduced the seed germination rate. Further analyses with transgenic B. rapa lines overexpressing BrEXLB1 sense (OX) and antisense transcripts (OX-AS) confirmed that BrEXLB1 overexpression is positively associated with drought tolerance and photosynthesis during vegetative growth phases of B. rapa plants. Moreover, the altered expression of BrEXLB1 in transgenic lines differentially influenced the expression of predicted BrEXLB1 interacting genes like Bra001852 and Bra003006. Collectively, this study revealed that BrEXLB1 is associated with root development, drought tolerance, photosynthesis, and seed germination.

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The Ca2+ sensor protein CMI1 fine tunes root development, auxin distribution and responses

10.1101/488536 ◽

2018 ◽

Author(s):

Ora Hazak ◽

Elad Mamon ◽

Meirav Lavy ◽

Hasana Sternberg ◽

Smrutisanjita Behera ◽

...

Keyword(s):

Root Growth ◽

Root Development ◽

Lateral Root ◽

Developmental Plasticity ◽

Molecular Mechanisms ◽

Ectopic Expression ◽

Growth Arrest ◽

Root Hairs ◽

Root Tip ◽

Auxin Distribution

Signaling cross-talks between auxin, a regulator of plant development and Ca2+, a universal second messenger have been proposed to modulate developmental plasticity in plants. However, the underlying molecular mechanisms are largely unknown. Here we report that in Arabidopsis roots, auxin elicits specific Ca2+ signaling pattern that spatially coincide with the expression pattern of auxin-regulated genes. We identified the EF-hand protein CMI1 (Ca2+ sensor Modulator of ICR1) as an interactor of the ROP effector ICR1 (Interactor of Constitutively active ROP). CMI1 is monomeric in solution, changes its secondary structure at Ca2+ concentrations ranging from 10-9 to 10-8 M and its interaction with ICR1 is Ca2+ dependent, involving a conserved hydrophobic pocket. cmi1 mutants display an increased auxin response including shorter primary roots, longer root hairs, longer hypocotyls and altered lateral root formation while ectopic expression of CMI1 induces root growth arrest and reduced auxin responses at the root tip. When expressed alone, CMI1 is localized at the plasma membrane, the cytoplasm and in nuclei. Interaction of CMI1 and ICR1 results in exclusion of CMI1 from nuclei and suppression of the root growth arrest. CMI1 expression is directly upregulated by auxin while expression of auxin induced genes is enhanced in cmi1 concomitantly with repression of auxin induced Ca2+ increases in the lateral root cap and vasculature, indicating that CMI1 represses early auxin responses. Collectively, our findings identify a crucial function of Ca2+ signaling and CMI1 in root growth and suggest an auxin-Ca2+ regulatory feedback loop that fine tunes root development.

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Individual and combined phytotoxic effects of cadmium, lead and arsenic on soybean in Phaeozem

Plant Soil and Environment ◽

10.17221/409-pse ◽

2008 ◽

Vol 54 (No. 9) ◽

pp. 403-411 ◽

Cited By ~ 17

Author(s):

Z.Q. Luan ◽

H.C. Cao ◽

B.X. Yan

Keyword(s):

Glycine Max ◽

Seed Germination ◽

Root Growth ◽

Shoot Growth ◽

Effective Concentration ◽

Toxicity Tests ◽

Response Relationship ◽

Antagonistic Effects ◽

Cadmium Lead ◽

The Individual

Acute laboratory toxicity tests were carried out to assess the individual and combined toxic effects of metals including cadmium (Cd), lead (Pb) and the metalloid arsenic (As) in Phaeozem on the seed germination and seedling growth of soybean, Glycine max Seeds were exposed to varied concentrations of Cd, Pb and As individually and in mixtures including Cd + Pb, Cd + As, Pb + As and Cd + Pb + As. The sum of toxic units (TU) for medium effective concentration of the mixture (EC50mix) was calculated based on the dose (TU-based)-response relationship using the Trimmed Spearman-Karber method. Binary metal combinations of Cd + Pb, Cd + As and Pb + As produced additive, synergistic and antagonistic effects, respectively, on shoot growth and synergistic, synergistic and antagonistic effects on root growth. Ternary combination of Cd + Pb + As had a synergistic effect on shoot growth and an additive effect on root growth. Bioaccumulation of metals was observed in soybean and inhibited or enhanced bioaccumulations of individual metals were found in mixtures due to different combinations of metals.

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Role of Ascorbate in the Regulation of the Arabidopsis thaliana Root Growth by Phosphate Availability

Journal of Botany ◽

10.1155/2012/580342 ◽

2012 ◽

Vol 2012 ◽

pp. 1-11 ◽

Cited By ~ 12

Author(s):

Jarosław Tyburski ◽

Kamila Dunajska-Ordak ◽

Monika Skorupa ◽

Andrzej Tretyn

Keyword(s):

Root Growth ◽

Lateral Root ◽

Root Elongation ◽

Lateral Roots ◽

Primary Root ◽

Root Hairs ◽

P Availability ◽

Root Tips ◽

P Deficiency ◽

Phosphate Availability

Arabidopsis root system responds to phosphorus (P) deficiency by decreasing primary root elongation and developing abundant lateral roots. Feeding plants with ascorbic acid (ASC) stimulated primary root elongation in seedlings grown under limiting P concentration. However, at high P, ASC inhibited root growth. Seedlings of ascorbate-deficient mutant (vtc1) formed short roots irrespective of P availability. P-starved plants accumulated less ascorbate in primary root tips than those grown under high P. ASC-treatment stimulated cell divisions in root tips of seedlings grown at low P. At high P concentrations ASC decreased the number of mitotic cells in the root tips. The lateral root density in seedlings grown under P deficiency was decreased by ASC treatments. At high P, this parameter was not affected by ASC-supplementation. vtc1 mutant exhibited increased lateral root formation on either, P-deficient or P-sufficient medium. Irrespective of P availability, high ASC concentrations reduced density and growth of root hairs. These results suggest that ascorbate may participate in the regulation of primary root elongation at different phosphate availability via its effect on mitotic activity in the root tips.

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Bokashi leachate as a biopriming on Basella rubra L. seed germination and root development

10.21203/rs.3.rs-855828/v1 ◽

2021 ◽

Author(s):

Phooi Chooi Lin ◽

Elisa Azura Azman ◽

Roslan Ismail

Keyword(s):

Seed Germination ◽

Root Growth ◽

Food Waste ◽

Root Development ◽

Germination Rate ◽

Germination Percentage ◽

Growth And Yield ◽

High Nutrient ◽

The Mean ◽

Improve Seed Germination

Abstract Basella rubra L. is a type of spinach, which is edible with high nutrient composition. It is also known to be an antioxidant. However, initial germination and root growth remain an issue due to hard exterior seed coating. Thus, some may germinate within 10 to 21 days, and some may not work at all. Inhibited growth may lead to vegetative propagation and micropropagation, which fundamentally reduce the growth and yield. Basella seed treated with Bokashi leachate was found to improve seed germination and root growth. A study was conducted using food waste EM Bokashi leachate (0:1, 1:1500, 1:1000, 1:500) with biopriming duration (6 and 12 hours). The experiment was conducted in a completely random design (CRD) with 3 replications of 100 seeds, with 24 experimental units. Based on the results, a short biopriming duration (6 hours) significantly enhanced the mean germination rate, germination speed accumulated, and coefficient of germination velocity. However, germination percentage had no significant improvement by leachate. Long priming duration significantly reduced the root development due to the seed may loss of desiccation tolerance. The concentration of leachate and priming duration had no significant interaction. In order to improve the germination and root growth performance, 6 hours of seeds priming duration or 1:500 (0.2%) of food waste Bokashi leachate was recommended to soak the Basella rubra seeds.

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Momilactone B inhibits Arabidopsis growth and development via disruption of ABA and auxin signaling

10.1101/2020.09.30.320655 ◽

2020 ◽

Author(s):

Jianxin Wu ◽

Jun Long ◽

Xianhui Lin ◽

Zhenyi Chang ◽

Scott R. Baerson ◽

...

Keyword(s):

Seed Germination ◽

Root Growth ◽

Growth And Development ◽

Auxin Signaling ◽

Inhibitory Effects ◽

Root Tips ◽

Transcriptional Responses ◽

Transcript Levels ◽

Meristematic Activity ◽

Aba Insensitive

AbstractIn competition for limited resources, many plants release allelochemicals to inhibit the growth of neighboring plants. Momilactone B (MB) is a major allelochemical produced by rice (Oryza sativa), however its mode of action is currently unknown. We used Arabidopsis (Arabidopsis thaliana) as a model system to evaluate potential mechanisms underlying the inhibitory effects of MB on seed germination, seedling establishment and root growth through the use of confocal microscopy and the examination of transcriptional responses in MB-treated seedlings. In response to MB treatment, transcript levels for genes encoding several key ABA biosynthetic enzymes and signaling components, including the transcription factor ABA-INSENSITIVE 4 (ABI4), were dramatically increased. Additionally, ABA insensitive 4 (abi4) mutant seedlings exhibited reduced susceptibility to exogenously-provided MB. Although the transcript levels of DELLA genes, which negatively regulate GA signaling, were significantly increased upon MB exposure, exogenous GA application did not reverse the inhibitory effects of MB on Arabidopsis germination and seedling development. Moreover, a reduction in seedling root meristematic activity, associated with reduced expression of auxin biosynthetic genes and efflux transporters, and apparent lowered auxin content, was observed in MB-treated root tips. Exogenous auxin applications partially rescued the inhibitory effects of MB observed in root growth. Our results indicate that MB suppresses Arabidopsis seed germination and root growth primarily via disruption of ABA and auxin signaling. These findings underscore the crucial roles played by phytohormones in mediating responses to allelochemical exposure.One-sentence summaryMomilactone B, the key allelochemical of rice, inhibits Arabidopsis growth and development via disruption of ABA and auxin signaling, suggesting the crucial roles of phytohormones in plant allelopathy

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The piperazine compound ASP activates an auxin response in Arabidopsis thaliana

BMC Genomics ◽

10.1186/s12864-020-07203-8 ◽

2020 ◽

Vol 21 (1) ◽

Author(s):

Fengyang Xu ◽

Shuqi Xue ◽

Limeng Deng ◽

Sufen Zhang ◽

Yaxuan Li ◽

...

Keyword(s):

Root Growth ◽

Root Development ◽

Gene Knockout ◽

Primary Root ◽

Inhibitory Effect ◽

Root Tip ◽

Ethylene Response Factor ◽

Auxin Response ◽

Root Tips ◽

Chemical Library

Abstract Background Auxins play key roles in the phytohormone network. Early auxin response genes in the AUX/IAA, SAUR, and GH3 families show functional redundancy, which makes it very difficult to study the functions of individual genes based on gene knockout analysis or transgenic technology. As an alternative, chemical genetics provides a powerful approach that can be used to address questions relating to plant hormones. Results By screening a small-molecule chemical library of compounds that can induce abnormal seedling and vein development, we identified and characterized a piperazine compound 1-[(4-bromophenoxy) acetyl]-4-[(4-fluorophenyl) sulfonyl] piperazine (ASP). The Arabidopsis DR5::GFP line was used to assess if the effects mentioned were correlated with the auxin response, and we accordingly verified that ASP altered the auxin-related pathway. Subsequently, we examined the regulatory roles of ASP in hypocotyl and root development, auxin distribution, and changes in gene expression. Following ASP treatment, we detected hypocotyl elongation concomitant with enhanced cell elongation. Furthermore, seedlings showed retarded primary root growth, reduced gravitropism and increased root hair development. These phenotypes were associated with an increased induction of DR5::GUS expression in the root/stem transition zone and root tips. Auxin-related mutants including tir1–1, aux1–7 and axr2–1 showed phenotypes with different root-development pattern from that of the wild type (Col-0), and were insensitive to ASP. Confocal images of propidium iodide (PI)-stained root tip cells showed no detectable damage by ASP. Furthermore, RT-qPCR analyses of two other genes, namely, Ethylene Response Factor (ERF115) and Mediator 18 (MED18), which are related to cell regeneration and damage, indicated that the ASP inhibitory effect on root growth was not attributable to toxicity. RT-qPCR analysis provided further evidence that ASP induced the expression of early auxin-response-related genes. Conclusions ASP altered the auxin response pathway and regulated Arabidopsis growth and development. These results provide a basis for dissecting specific molecular components involved in auxin-regulated developmental processes and offer new opportunities to discover novel molecular players involved in the auxin response.

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Effects of salinity stress on seed germination and root growth of seedlings in island cotton

ACTA AGRONOMICA SINICA ◽

10.3724/sp.j.1006.2019.84067 ◽

2019 ◽

Vol 45 (1) ◽

pp. 100

Author(s):

Qing-Qing YAN ◽

Ju-Song ZHANG ◽

Xing-Xing LI ◽

Yan-Ti WANG

Keyword(s):

Seed Germination ◽

Root Growth ◽

Salinity Stress ◽

Growth Of Seedlings

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A low-cost aeroponic phenotyping system for storage root development: unravelling the below-ground secrets of cassava (Manihot esculenta)

Plant Methods ◽

10.1186/s13007-019-0517-6 ◽

2019 ◽

Vol 15 (1) ◽

Cited By ~ 4

Author(s):

Michael Gomez Selvaraj ◽

Maria Elker Montoya-P ◽

John Atanbori ◽

Andrew P. French ◽

Tony Pridmore

Keyword(s):

Root Growth ◽

Root Development ◽

Low Cost ◽

Root Traits ◽

Suitable Model ◽

Root Initiation ◽

Storage Root ◽

Economic Traits ◽

Storage Roots ◽

Storage Root Development

Abstract Background Root and tuber crops are becoming more important for their high source of carbohydrates, next to cereals. Despite their commercial impact, there are significant knowledge gaps about the environmental and inherent regulation of storage root (SR) differentiation, due in part to the innate problems of studying storage roots and the lack of a suitable model system for monitoring storage root growth. The research presented here aimed to develop a reliable, low-cost effective system that enables the study of the factors influencing cassava storage root initiation and development. Results We explored simple, low-cost systems for the study of storage root biology. An aeroponics system described here is ideal for real-time monitoring of storage root development (SRD), and this was further validated using hormone studies. Our aeroponics-based auxin studies revealed that storage root initiation and development are adaptive responses, which are significantly enhanced by the exogenous auxin supply. Field and histological experiments were also conducted to confirm the auxin effect found in the aeroponics system. We also developed a simple digital imaging platform to quantify storage root growth and development traits. Correlation analysis confirmed that image-based estimation can be a surrogate for manual root phenotyping for several key traits. Conclusions The aeroponic system developed from this study is an effective tool for examining the root architecture of cassava during early SRD. The aeroponic system also provided novel insights into storage root formation by activating the auxin-dependent proliferation of secondary xylem parenchyma cells to induce the initial root thickening and bulking. The developed system can be of direct benefit to molecular biologists, breeders, and physiologists, allowing them to screen germplasm for root traits that correlate with improved economic traits.

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Non-TZF Protein AtC3H59/ZFWD3 Is Involved in Seed Germination, Seedling Development, and Seed Development, Interacting with PPPDE Family Protein Desi1 in Arabidopsis

International Journal of Molecular Sciences ◽

10.3390/ijms22094738 ◽

2021 ◽

Vol 22 (9) ◽

pp. 4738

Author(s):

Hye-Yeon Seok ◽

Hyungjoon Bae ◽

Taehyoung Kim ◽

Syed Muhammad Muntazir Mehdi ◽

Linh Vu Nguyen ◽

...

Keyword(s):

Seed Germination ◽

Seed Development ◽

Zinc Finger ◽

Root Length ◽

Primary Root ◽

Seedling Development ◽

Ccch Zinc Finger ◽

Family Protein ◽

Wd40 Domain ◽

Primary Root Length

Despite increasing reports on the function of CCCH zinc finger proteins in plant development and stress response, the functions and molecular aspects of many non-tandem CCCH zinc finger (non-TZF) proteins remain uncharacterized. AtC3H59/ZFWD3 is an Arabidopsis non-TZF protein and belongs to the ZFWD subfamily harboring a CCCH zinc finger motif and a WD40 domain. In this study, we characterized the biological and molecular functions of AtC3H59, which is subcellularly localized in the nucleus. The seeds of AtC3H59-overexpressing transgenic plants (OXs) germinated faster than those of wild type (WT), whereas atc3h59 mutant seeds germinated slower than WT seeds. AtC3H59 OX seedlings were larger and heavier than WT seedlings, whereas atc3h59 mutant seedlings were smaller and lighter than WT seedlings. Moreover, AtC3H59 OX seedlings had longer primary root length than WT seedlings, whereas atc3h59 mutant seedlings had shorter primary root length than WT seedlings, owing to altered cell division activity in the root meristem. During seed development, AtC3H59 OXs formed larger and heavier seeds than WT. Using yeast two-hybrid screening, we isolated Desi1, a PPPDE family protein, as an interacting partner of AtC3H59. AtC3H59 and Desi1 interacted via their WD40 domain and C-terminal region, respectively, in the nucleus. Taken together, our results indicate that AtC3H59 has pleiotropic effects on seed germination, seedling development, and seed development, and interacts with Desi1 in the nucleus via its entire WD40 domain. To our knowledge, this is the first report to describe the biological functions of the ZFWD protein and Desi1 in Arabidopsis.

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