Root gravitropism is regulated by a transient lateral auxin gradient controlled by a tipping-point mechanism

被引：236

作者：

Band, Leah R. ^{[2
]}

Wells, Darren M. ^{[2
]}

Larrieu, Antoine ^{[2
]}

Sun, Jianyong ^{[2
]}

Middleton, Alistair M. ^{[3
]}

French, Andrew P. ^{[2
]}

Brunoud, Geraldine ^{[1
]}

Sato, Ethel Mendocilla ^{[2
,4
]}

Wilson, Michael H. ^{[2
]}

Peret, Benjamin ^{[2
]}

Oliva, Marina ^{[1
]}

Swarup, Ranjan ^{[2
]}

Sairanen, Ilkka ^{[5
]}

Parry, Geraint ^{[6
]}

Ljung, Karin ^{[5
]}

Beeckman, Tom ^{[7
]}

Garibaldi, Jonathan M. ^{[2
]}

Estelle, Mark ^{[8
,9
]}

Owen, Markus R. ^{[2
]}

Vissenberg, Kris ^{[4
]}

Hodgman, T. Charlie ^{[2
]}

Pridmore, Tony P. ^{[2
]}

King, John R. ^{[2
]}

Vernoux, Teva ^{[1
]}

Bennett, Malcolm J. ^{[2
]}

机构：

[1] Univ Lyon 1, Ecole Normale Super Lyon, Lab Reprod & Dev Plantes, Ctr Natl Rech Sci,Inst Natl Rech Agron, F-69364 Lyon, France

[2] Univ Nottingham, Ctr Plant Integrat Biol, Loughborough LE12 5RD, Leics, England

[3] Univ Freiburg, Ctr Biol Syst Anal, D-79104 Freiburg, Germany

[4] Univ Antwerp, Dept Biol, B-2020 Antwerp, Belgium

[5] Swedish Univ Agr Sci, Dept Forest Genet & Plant Physiol, Umea Plant Sci Ctr, SE-90183 Umea, Sweden

[6] Univ Liverpool, Inst Integrat Biol, Liverpool L69 7ZB, Merseyside, England

[7] Univ Ghent VIB, Dept Plant Syst Biol, B-9052 Ghent, Belgium

[8] Indiana Univ, Dept Biol, Bloomington, IN 47405 USA

[9] Univ Calif San Diego, Div Biol, La Jolla, CA 92122 USA

来源：

PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA | 2012年 / 109卷 / 12期

基金：

英国生物技术与生命科学研究理事会; 美国国家卫生研究院; 英国工程与自然科学研究理事会;

关键词：

environmental sensing; systems biology; BOX PROTEIN TIR1; SEDIMENTATION KINETICS; ENDOPLASMIC-RETICULUM; AUX/IAA PROTEINS; GENE-EXPRESSION; ARABIDOPSIS; GRAVITY; TRANSPORT; GROWTH; CELLS;

D O I：

10.1073/pnas.1201498109

中图分类号：

O [数理科学和化学]; P [天文学、地球科学]; Q [生物科学]; N [自然科学总论];

学科分类号：

07 ; 0710 ; 09 ;

摘要：

Gravity profoundly influences plant growth and development. Plants respond to changes in orientation by using gravitropic responses to modify their growth. Cholodny and Went hypothesized over 80 years ago that plants bend in response to a gravity stimulus by generating a lateral gradient of a growth regulator at an organ's apex, later found to be auxin. Auxin regulates root growth by targeting Aux/IAA repressor proteins for degradation. We used an Aux/IAA-based reporter, domain II (DII)-VENUS, in conjunction with a mathematical model to quantify auxin redistribution following a gravity stimulus. Our multidisciplinary approach revealed that auxin is rapidly redistributed to the lower side of the root within minutes of a 90 degrees gravity stimulus. Unexpectedly, auxin asymmetry was rapidly lost as bending root tips reached an angle of 40 degrees to the horizontal. We hypothesize roots use a "tipping point" mechanism that operates to reverse the asymmetric auxin flow at the midpoint of root bending. These mechanistic insights illustrate the scientific value of developing quantitative reporters such as DII-VENUS in conjunction with parameterized mathematical models to provide high-resolution kinetics of hormone redistribution.

引用

页码：4668 / 4673

页数：6

共 38 条

[31] Root gravitropism requires lateral root cap and epidermal cells for transport and response to a mobile auxin signal [J].