ArabidopsisCytokinin Receptor Mutants Reveal Functions in Shoot Growth, Leaf Senescence, Seed Size, Germination, Root Development, and Cytokinin Metabolism

Plant Cell - Tập 18 Số 1 - Trang 40-54 - 2005
Michael Riefler1, Ondřej Novák2, Miroslav Strnad2, Thomas Schmülling1
1Institute of Biology/Applied Genetics, Free University of Berlin, D-14195 Berlin, Germany
2Laboratory of Growth Regulators, Palacký University and Institute of Experimental Botany, Academy of Sciences of the Czech Republic, CZ-78371 Olomouc, Czech Republic

Tóm tắt

AbstractWe used loss-of-function mutants to study three Arabidopsis thaliana sensor histidine kinases, AHK2, AHK3, and CRE1/AHK4, known to be cytokinin receptors. Mutant seeds had more rapid germination, reduced requirement for light, and decreased far-red light sensitivity, unraveling cytokinin functions in seed germination control. Triple mutant seeds were more than twice as large as wild-type seeds. Genetic analysis indicated a cytokinin-dependent endospermal and/or maternal control of embryo size. Unchanged red light sensitivity of mutant hypocotyl elongation suggests that previously reported modulation of red light signaling by A-type response regulators may not depend on cytokinin. Combined loss of AHK2 and AHK3 led to the most prominent changes during vegetative development. Leaves of ahk2 ahk3 mutants formed fewer cells, had reduced chlorophyll content, and lacked the cytokinin-dependent inhibition of dark-induced chlorophyll loss, indicating a prominent role of AHK2 and, particularly, AHK3 in the control of leaf development. ahk2 ahk3 double mutants developed a strongly enhanced root system through faster growth of the primary root and, more importantly, increased branching. This result supports a negative regulatory role for cytokinin in root growth regulation. Increased cytokinin content of receptor mutants indicates a homeostatic control of steady state cytokinin levels through signaling. Together, the analyses reveal partially redundant functions of the cytokinin receptors and prominent roles for the AHK2/AHK3 receptor combination in quantitative control of organ growth in plants, with opposite regulatory functions in roots and shoots.

Từ khóa


Tài liệu tham khảo

2003, Science, 301, 653, 10.1126/science.1086391

1999, Proc. Natl. Acad. Sci. USA, 96, 4710, 10.1073/pnas.96.8.4710

2001, Trends Biochem. Sci., 10, 579

2004, Plant Physiol., 134, 1624, 10.1104/pp.103.036897

2002

1998, Plant J., 16, 697, 10.1046/j.1365-313x.1998.00340.x

1952, Proc. Natl. Acad. Sci. USA, 38, 662, 10.1073/pnas.38.8.662

2005, Plant J., 44, 314, 10.1111/j.1365-313X.2005.02530.x

2005, Plant J., 42, 567, 10.1111/j.1365-313X.2005.02399.x

2003, Trends Plant Sci., 8, 165, 10.1016/S1360-1385(03)00051-7

1994, Plant Physiol., 104, 339, 10.1104/pp.104.2.339

2000, Plant Physiol., 124, 1706, 10.1104/pp.124.4.1706

2003, Plant J., 33, 543, 10.1046/j.1365-313X.2003.01652.x

1997, Plant J., 12, 401, 10.1046/j.1365-313X.1997.12020401.x

2005, Curr. Opin. Plant Biol., 8, 518, 10.1016/j.pbi.2005.07.013

2002, Plant J., 32, 353, 10.1046/j.1365-313X.2002.01431.x

1995, Science, 270, 1986, 10.1126/science.270.5244.1986

2005, Plant Cell, 17, 52, 10.1105/tpc.104.027136

2004, Plant J., 38, 70, 10.1111/j.1365-313X.2004.02023.x

2005, Plant Cell, 17, 92, 10.1105/tpc.104.028472

2004, Planta, 219, 733

2003, Curr. Opin. Plant Biol., 6, 480, 10.1016/S1369-5266(03)00087-6

2004, Proc. Natl. Acad. Sci. USA, 101, 8821, 10.1073/pnas.0402887101

2002, Plant Physiol., 129, 500, 10.1104/pp.005504

2001, Nature, 413, 383, 10.1038/35096500

2001, Nature, 409, 1060, 10.1038/35059117

2005, Proc. Natl. Acad. Sci. USA, 102, 3117, 10.1073/pnas.0409893102

2003, Annu. Rev. Plant Biol., 54, 605, 10.1146/annurev.arplant.54.031902.134802

1992, Plant Cell Rep., 11, 118

1985, Physiol. Plant., 65, 33, 10.1111/j.1399-3054.1985.tb02355.x

1994, 313

2004, Plant J., 38, 203, 10.1111/j.1365-313X.2004.02038.x

2003, Curr. Opin. Plant Biol., 6, 280, 10.1016/S1369-5266(03)00035-9

1995, Plant Physiol., 109, 7, 10.1104/pp.109.1.7

1997, Physiol. Plant., 100, 613, 10.1111/j.1399-3054.1997.tb03067.x

2000, Genes Dev., 14, 2938, 10.1101/gad.189200

1993, 349

2004, Plant J., 38, 779, 10.1111/j.1365-313X.2004.02079.x

1956, J. Am. Chem. Soc., 78, 1345

1994, 129

1958, Flora, 146, 521

2001, Trends Biochem. Sci., 26, 582, 10.1016/S0968-0004(01)01969-7

1998, Plant Physiol., 118, 27, 10.1104/pp.118.1.27

2004, Plant Cell, 16, 1365, 10.1105/tpc.021477

2003, Anal. Chim. Acta, 480, 207, 10.1016/S0003-2670(03)00025-4

2005, Proc. Natl. Acad. Sci. USA, 102, 3123, 10.1073/pnas.0409858102

1989, Biochim. Biophys. Acta, 975, 384, 10.1016/S0005-2728(89)80347-0

2003, Plant Physiol., 132, 1998, 10.1104/pp.103.021436

1994, Plant Physiol., 104, 1139, 10.1104/pp.104.4.1139

1957, Science, 125, 650, 10.1126/science.125.3249.650.a

2003, Plant Mol. Biol., 53, 247, 10.1023/B:PLAN.0000009297.37235.4a

1995, Development, 121, 53, 10.1242/dev.121.1.53

2002, Plant Cell, 14, 2985, 10.1105/tpc.004630

1994, Plant Cell Physiol., 2, 363

2004, Plant Cell Physiol., 45, 1299, 10.1093/pcp/pch132

2001, Plant Cell Physiol., 42, 107, 10.1093/pcp/pce037

2001, Science, 294, 1108, 10.1126/science.1065022

2004, Plant Cell, 16, 658, 10.1105/tpc.018978

2003, Curr. Opin. Plant Biol., 6, 57, 10.1016/S1369526602000055

2001, Plant Cell Physiol., 42, 751, 10.1093/pcp/pce094

1994, Eur. J. Biochem., 224, 771, 10.1111/j.1432-1033.1994.00771.x

2003, Plant Cell, 15, 2532, 10.1105/tpc.014928

2001, Proc. Natl. Acad. Sci. USA, 98, 10487, 10.1073/pnas.171304098

2001, Plant Cell Physiol., 42, 1017, 10.1093/pcp/pce127

1998, Plant Cell, 10, 2115

2003, Plant Mol. Biol., 51, 237, 10.1023/A:1021115816540

Thông tin
Thông tin xuất bản

Plant Cell

Tập 18 Số 1

40-54

Thông tin tác giả