pH dependent Cu(II) and Pd(II) ions detection and removal from aqueous media by an efficient mesoporous adsorbent

Awual, M. R.; Rahman, I. M. M.*; Yaita, Tsuyoshi; Khaleque, M. A.*; Ferdows, M.*

Chemical Engineering Journal, 236, p.100 - 109, 2014/01

https://doi.org/10.1016/j.cej.2013.09.083

SMALL ACIDIC PROTEIN 1 acts with RUB modification components the COP9 signalosome and AXR1 to regulate growth and development of

Nakasone, Akari*; Fujiwara, Masayuki*; Fukao, Yoichiro*; Biswas, K.; Rahman, A.*; Yamada, Maki*; Narumi, Issei; Uchimiya, Hirofumi*; Ono, Yutaka

Plant Physiology, 160(1), p.93 - 105, 2012/09

https://doi.org/10.1104/pp.111.188409

Genetic dissection of hormonal responses in the roots of arabidopsis grown under continuous mechanical impedance

Okamoto, Takashi*; Tsurumi, Seiji*; Shibasaki, Kyohei*; Obana, Yoshimi*; Takaji, Hironori*; Ono, Yutaka; Rahman, A.*

Plant Physiology, 146(4), p.1651 - 1662, 2008/04

https://doi.org/10.1104/pp.107.115519

The Arabidopsis seedlings grown horizontally on a dialysis membrane-covered agar plate encountered adequate mechanical impedance as the roots showed characteristic ethylene phenotypes: 2-fold reduction in root growth, increase in root diameter, decrease in cell elongation, and ectopic root hair formation. The root phenotype characterization of various mutants having altered response to ethylene biosynthesis or signaling, the effect of ethylene inhibitors on mechanically impeded roots, and transcription profiling of the ethylene-responsive genes led us to conclude that enhanced ethylene response plays a primary role in changing root morphology and development during mechanical impedance. Further, the differential sensitivity of horizontally and vertically grown roots toward exogenous ethylene suggested that ethylene signaling plays a critical role in enhancing the ethylene response. We subsequently demonstrated that the enhanced ethylene response also affects the auxin response in roots. Taken together, our results provide a new insight into the role of ethylene in changing root morphology during mechanical impedance.

A Small acidic protein 1 (SMAP1) mediates responses of the arabidopsis root to the synthetic auxin 2,4-dichlorophenoxyacetic acid

Rahman, A.*; Nakasone, Akari*; Chhun, T.*; Oura, Chiharu*; Biswas, K. K.*; Uchimiya, Hirofumi*; Tsurumi, Seiji*; Baskin, T. I.*; Tanaka, Atsushi; Ono, Yutaka

Plant Journal, 47(5), p.788 - 801, 2006/09

https://doi.org/10.1111/j.1365-313X.2006.02832.x

2,4-D, a chemical analogue of IAA, is widely used as a growth regulator and exogenous source of auxin. It is believed that they share a common response pathway. Here, we show that a mutant, () is resistant to 2,4-D, yet nevertheless responds like the wild type to IAA. That the mutation alters 2,4-D responsiveness specifically was confirmed by analysis of GUS expression in the and backgrounds, as well as by real-time PCR quantification of expression. Complementation and RNAi experiments identified a gene that confers 2,4-D responsiveness. The gene encodes a with unknown function and present in plants, animals, and invertebrates. These results suggest that SMAP1 is a regulatory component that mediates responses to 2,4-D and that responsiveness to 2,4-D and IAA are partially distinct.

SMALL ACIDIC PROTEIN 1 acts with RUB modification components, the COP9 signalosome and AXR1, to regulate growth and development of

Ono, Yutaka; Nakasone, Akari*; Fujiwara, Masayuki*; Fukao, Yoichiro*; Biswas, K.; Rahman, A.*; Kawai, Maki*; Uchimiya, Hirofumi*; Narumi, Issei

no journal, , 

Continuous mechanical impedance enhances ethylene response rather than ethylene production in Arabidopsis roots

Okamoto, Takashi*; Rahman, A.*; Ono, Yutaka; Tsurumi, Seiji*

no journal, , 

We investigated the role of hormones in regulating the growth and morphology of roots during mechanical impedance using the model plant Arabidopsis thaliana. The Arabidopsis seedlings were grown horizontally on a dialysis membrane-covered agar plate to be exposed to mechanical impedance. The roots showed a characteristic ethylene phenotype; 0.5-fold reduction in root growth, 1.2-fold increase in root diameter, 0.5-fold decrease in cell elongation and ectopic root hair formation. The characterization of roots suggested that enhanced ethylene response plays a primary role in changing the root morphology and development during mechanical impedance. We also provided evidence that ethylene signaling rather than ethylene synthesis plays a pivotal role in enhancing the ethylene response. Our results provide a mechanistic explanation of the role of ethylene in changing the root morphology during mechanical impedance.

Genetic dissection of hormonal responses in the roots of grown under continuous mechanical impedance

Okamoto, Takashi*; Tsurumi, Seiji*; Shibasaki, Kyohei*; Ono, Yutaka; Rahman, A.*

no journal, , 

The seedlings grown on a dialysis membrane-covered agar plate encountered adequate mechanical impedance to the roots showed characteristic ethylene phenotypes. Detailed characterization of this phenotype suggested that ethylene signaling, rather than ethylene production plays a critical role in enhancing the ethylene response. We subsequently demonstrated that the enhanced ethylene response also affects the auxin response in root. Our results provide a new insight into the role of ethylene in changing root morphology during mechanical impedance.

Characterization of mutants; A Small acidic protein 1 (SMAP1) that mediates responses of the arabidopsis root to the synthetic auxin 2,4-dichlorophenoxyacetic acid

Ono, Yutaka; Rahman, A.*; Biswas, K. K.*; Chhun, T.*; Tsurumi, Seiji*; Narumi, Issei

no journal, , 

The mechanism of plant hormoneauxin action has been revealed by identification of several auxin-related mutants. However, the detailed regulatory system of signaling pathway and whether known auxin receptors TIR1/AFBs accounts for all auxin response largely remains unclear. It is may be possible that other uncharacterized proteins are involved in TIR1/AFBs dependent or independent auxin signaling pathway. To investigate novel factors involved in auxin signaling, we screened new mutants that exhibits a long primary root in presence of antiauxin PCIB. The mutants were classified at least 5 independent loci including two known auxin-related loci and . Furthermore, physiological and molecular characterization of a novel auxin-related mutants, suggested that small acidic protein 1 is a regulatory component that mediates 2,4-D-induced auxin response and mode of action of 2,4-D is distinct from that of IAA at least in part.

Root morphology and hormonal response in grown under the continuous mechanical stimulation

Okamoto, Takashi*; Rahman, A.*; Ono, Yutaka; Tsurumi, Seiji*

no journal, , 

We have previously proposed a new and simple growing system to dissect morphology and elongation by continuous mechanical stimulation on roots: roots are allowed to grow on dialysis membrane-covered agar plate placed horizontally, resulting in providing continuous mechanical stimulation upon root tip during bending downward. Growth of horizontally grown seedlings was found to be almost half as compared to that of vertical control and the reduced elongation of horizontal roots was attributed to enhancement of the ethylene response without that of the ethylene production. The role of auxin in the morphology will also be discussed based on and expression study and the estimation of auxin responsive genes by real-time PCR.