scholarly journals Overexpression of OsPIN2 Regulates Root Growth and Formation in Response to Phosphate Deficiency in Rice

2019 ◽  
Vol 20 (20) ◽  
pp. 5144
Author(s):  
Huwei Sun ◽  
Xiaoli Guo ◽  
Fugui Xu ◽  
Daxia Wu ◽  
Xuhong Zhang ◽  
...  

The response of root architecture to phosphate (P) deficiency is critical in plant growth and development. Auxin is a key regulator of plant root growth in response to P deficiency, but the underlying mechanisms are unclear. In this study, phenotypic and genetic analyses were undertaken to explore the role of OsPIN2, an auxin efflux transporter, in regulating the growth and development of rice roots under normal nutrition condition (control) and low-phosphate condition (LP). Higher expression of OsPIN2 was observed in rice plants under LP compared to the control. Meanwhile, the auxin levels of roots were increased under LP relative to control condition in wild-type (WT) plants. Compared to WT plants, two overexpression (OE) lines had higher auxin levels in the roots under control and LP. LP led to increased seminal roots (SRs) length and the root hairs (RHs) density, but decreased lateral roots (LRs) density in WT plants. However, overexpression of OsPIN2 caused a loss of sensitivity in the root response to P deficiency. The OE lines had a shorter SR length, lower LR density, and greater RH density than WT plants under control. However, the LR and RH densities in the OE lines were similar to those in WT plants under LP. Compared to WT plants, overexpression of OsPIN2 had a shorter root length through decreased root cell elongation under control and LP. Surprisingly, overexpression of OsPIN2 might increase auxin distribution in epidermis of root, resulting in greater RH formation but less LR development in OE plants than in WT plants in the control condition but levels similar of these under LP. These results suggest that higher OsPIN2 expression regulates rice root growth and development maybe by changing auxin distribution in roots under LP condition.

Development ◽  
2020 ◽  
Vol 148 (1) ◽  
pp. dev190033
Author(s):  
Vibhav Gautam ◽  
Archita Singh ◽  
Sandeep Yadav ◽  
Sharmila Singh ◽  
Pramod Kumar ◽  
...  

ABSTRACTRoot system architecture and anatomy of monocotyledonous maize is significantly different from dicotyledonous model Arabidopsis. The molecular role of non-coding RNA (ncRNA) is poorly understood in maize root development. Here, we address the role of LEAFBLADELESS1 (LBL1), a component of maize trans-acting short-interfering RNA (ta-siRNA), in maize root development. We report that root growth, anatomical patterning, and the number of lateral roots (LRs), monocot-specific crown roots (CRs) and seminal roots (SRs) are significantly affected in lbl1-rgd1 mutant, which is defective in production of ta-siRNA, including tasiR-ARF that targets AUXIN RESPONSE FACTOR3 (ARF3) in maize. Altered accumulation and distribution of auxin, due to differential expression of auxin biosynthesis and transporter genes, created an imbalance in auxin signalling. Altered expression of microRNA165/166 (miR165/166) and its targets, ROLLED1 and ROLLED2 (RLD1/2), contributed to the changes in lbl1-rgd1 root growth and vascular patterning, as was evident by the altered root phenotype of Rld1-O semi-dominant mutant. Thus, LBL1/ta-siRNA module regulates root development, possibly by affecting auxin distribution and signalling, in crosstalk with miR165/166-RLD1/2 module. We further show that ZmLBL1 and its Arabidopsis homologue AtSGS3 proteins are functionally conserved.


2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Jarosław Tyburski ◽  
Kamila Dunajska-Ordak ◽  
Monika Skorupa ◽  
Andrzej Tretyn

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.


Plants ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1722
Author(s):  
Lidiya Vysotskaya ◽  
Guzel Akhiyarova ◽  
Arina Feoktistova ◽  
Zarina Akhtyamova ◽  
Alla Korobova ◽  
...  

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.


2021 ◽  
Vol 12 ◽  
Author(s):  
Daniel Gonzalez ◽  
Johannes Postma ◽  
Matthias Wissuwa

The rice root system develops a large number of nodal roots from which two types of lateral roots branch out, large L-types and fine S-types, the latter being unique to the species. All roots including S-types are covered by root hairs. To what extent these fine structures contribute to phosphate (P) uptake under P deficiency was investigated using a novel 3-D root growth model that treats root hairs as individual structures with their own Michaelis-Menten uptake kinetics. Model simulations indicated that nodal roots contribute most to P uptake followed by L-type lateral roots and S-type laterals and root hairs. This is due to the much larger root surface area of thicker nodal roots. This thickness, however, also meant that the investment in terms of P needed for producing nodal roots was very large. Simulations relating P costs and time needed to recover that cost through P uptake suggest that producing nodal roots represents a considerable burden to a P-starved plant, with more than 20 times longer pay-off time compared to S-type laterals and root hairs. We estimated that the P cost of these fine root structures is low enough to be recovered within a day of their formation. These results expose a dilemma in terms of optimizing root system architecture to overcome P deficiency: P uptake could be maximized by developing more nodal root tissue, but when P is growth-limiting, adding more nodal root tissue represents an inefficient use of the limiting factor P. In order to improve adaption to P deficiency in rice breeding two complementary strategies seem to exist: (1) decreasing the cost or pay-off time of nodal roots and (2) increase the biomass allocation to S-type roots and root hairs. To what extent genotypic variation exists within the rice gene pool for either strategy should be investigated.


PLoS ONE ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. e0244856
Author(s):  
Zhiwen Chen ◽  
Jianguo Zhao ◽  
Jie Song ◽  
Shenghua Han ◽  
Yaqin Du ◽  
...  

Graphene reportedly exerts positive effects on plant root growth and development, although the corresponding molecular response mechanism remains to be elucidated. Maize seeds were randomly divided into a control and experimental group, and the roots of Zea mays L. seedlings were watered with different concentrations (0–100 mg/L) of graphene to explore the effects and molecular mechanism of graphene on the growth and development of Z. mays L. Upon evaluating root growth indices, 50 mg/L graphene remarkably increased total root length, root volume, and the number of root tips and forks of maize seedlings compared to those of the control group. We observed that the contents of nitrogen and potassium in rhizosphere soil increased following the 50 mg/L graphene treatment. Thereafter, we compared the transcriptome changes in Z. mays roots in response to the 50 mg/L graphene treatment. Transcriptional factor regulation, plant hormone signal transduction, nitrogen and potassium metabolism, as well as secondary metabolism in maize roots subjected to graphene treatment, exhibited significantly upregulated expression, all of which could be related to mechanisms underlying the response to graphene. Based on qPCR validations, we proposed several candidate genes that might have been affected with the graphene treatment of maize roots. The transcriptional profiles presented here provide a foundation for deciphering the mechanism underlying graphene and maize root interaction.


2018 ◽  
Vol 19 (11) ◽  
pp. 3656 ◽  
Author(s):  
Hua Qin ◽  
Rongfeng Huang

Roots are important plant ground organs, which absorb water and nutrients to control plant growth and development. Phytohormones have been known to play a crucial role in the regulation of root growth, such as auxin and ethylene, which are central regulators of this process. Recent findings have revealed that root development and elongation regulated by ethylene are auxin dependent through alterations of auxin biosynthesis, transport and signaling. In this review, we focus on the recent advances in the study of auxin and auxin–ethylene crosstalk in plant root development, demonstrating that auxin and ethylene act synergistically to control primary root and root hair growth, but function antagonistically in lateral root formation. Moreover, ethylene modulates auxin biosynthesis, transport and signaling to fine-tune root growth and development. Thus, this review steps up the understanding of the regulation of auxin and ethylene in root growth.


2014 ◽  
Vol 33 (5) ◽  
pp. 745-753 ◽  
Author(s):  
Huiyu Tian ◽  
Yuebin Jia ◽  
Tiantian Niu ◽  
Qianqian Yu ◽  
Zhaojun Ding

1990 ◽  
Vol 8 (4) ◽  
pp. 215-220 ◽  
Author(s):  
Edward F. Gilman

Abstract Root form is governed by seedling genetics and soil characteristics including texture, compaction, depth to the water table, fertility, moisture content and other factors. Trees develop lateral roots growing parallel to the surface of the soil. These are generally located in the top 30 cm (12 in) of soil. Fine roots emerge from lateral roots and grow into the soil close to the surface. If soil conditions permit, some trees grow tap and other vertically oriented roots capable of penetrating several feet into the soil. Many trees, particularly those planted in urban landscapes, do not generate tap roots. Lateral roots spread to well beyond the edge of the branches. Their growth in governed by competition from other plants, available water, soil temperature, fertility, stage of shoot growth and other factors.


2021 ◽  
Author(s):  
Christine Kaufmann ◽  
Nils Stührwohldt ◽  
Margret Sauter

Tyrosine-sulfated peptides are key regulators of plant growth and development. The disulfated pentapeptide phytosulfokine (PSK) mediates growth via leucine-rich repeat receptor-like kinases, PSKR1 and PSKR2. PSKRs are part of a response module at the plasma membrane that mediates short-term growth responses, but downstream signaling of transcriptional regulation remains unexplored. In Arabidopsis, tyrosine sulfation is catalyzed by a single-copy gene (TPST). We performed a microarray-based transcriptome analysis in the tpst-1 mutant background that lacks sulfated peptides to identify PSK-regulated genes and genes that are regulated by other sulfated peptides. Of the 160 PSK-regulated genes, several had functions in root growth and development in agreement with shorter roots and a higher lateral root density in tpst-1. Further, tpst-1 roots developed higher numbers of root hairs and PSK induced expression of WEREWOLF (WER), its paralog MYB DOMAIN PROTEIN 23 (MYB23) and At1g66800 that maintain non-hair cell fate. The tpst-1 pskr1-3 pskr2-1 mutant showed even shorter roots, and higher lateral root and root hair density than tpst-1 revealing unexpected synergistic effects of ligand and PSK receptor deficiencies. While residual activities may exist, overexpression of PSKR1 in the tpst-1 background induced root growth suggesting that PSKR1 may be active in the absence of sulfated ligands.


Author(s):  
Caiwen Xue ◽  
Wenfeng Li ◽  
Ren Fang Shen ◽  
Ping Lan

Phosphate is essential for plant growth and development. Root architecture alternations induced by phosphate starvation (-Pi), including primary root and lateral root growth, are mediated by iron (Fe). However, whether and how Fe participates in the -Pi-induced root hair growth (RHG) remains unclear. Here, with morphological, proteomic, and pharmacological analysis, we investigate the impacts of Fe on RHG under -Pi and the underlying mechanisms. We found that -Pi-induced RHG was affected by the local Fe availability. Reduced sensitivity to Fe was found in aux1-7, arf10arf16, and phr1 under -Pi, indicating auxin and phosphate starvation-induced responses were required for the Fe-triggered RHG under -Pi. Fe availability was then found to affect the auxin distribution and expression of phosphate starvation-responsive (PSR) genes. Proteomic analysis indicated vesicle trafficking was affected by Fe under -Pi. With the application of brefeldin A, we found the vesicle trafficking was affected by Fe, and root hairs displayed reduced sensitivity to Fe, indicating the vesicle trafficking is critical for Fe-triggered RHG under -Pi. Our data suggested that Fe is involved in RHG under -Pi by integrating the vesicle trafficking, auxin distribution, and PSR. It further enriches the understanding of the interplay between phosphate and iron on RHG.


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