1. Front Cover.cdr - CORE

Recommendations

Info

A B S T R A C T B O O K – A B S T R A C T S O F T A L K S GRAVITROPISM OF ARABIDOPSIS THALIANA ROOTS REQUIRES THE POLARIZATION OF PIN2 TOWARD THE ROOT TIP IN MERISTEMATIC CORTICAL CELLS 31 X X I V S P P S C O N G R E S S 2 0 1 1 Session 5.Cell biology Abidur Rahman 1 , Maho Takahashi 1 ,Kyohei Shibasaki 1 , Shuang Wu 2 , Takehito Inaba 3 , Seiji Tsurumi 4 , Tobias I. Baskin 2 1 Cryobiofrontier Research Center, Faculty of Agriculture, Iwate University, Morioka, Iwate, Japan 2 Departmentof Biology, University of Massachusetts, Amherst, Massachusetts, USA 3 Interdisciplinary Research Organization, Faculty of Agriculture, University of Miyazaki, Miyazaki, Japan 4 Center for Supports to Research and Education Activities Isotope Division, Kobe University, Nada, Kobe, Japan E-mail: abidur@iwate-u.ac.jp In the root, the transport of auxin from the tip to the elongation zone, referred to here as shootward, governs gravitropic bending. Shootward polar auxin transport, and hence gravitropism, depends on the polar deployment of the PIN-FORMED auxin efflux carrier PIN2. In Arabidopsis thaliana, PIN2 has the expected shootward localization in epidermis and lateral root cap; however, this carrier is localized toward the root tip (rootward) in cortical cells of the meristem, a deployment whose function is enigmatic. We use pharmacological and genetic tools to cause a shootward relocation of PIN2 in meristematic cortical cells without detectably altering PIN2 polarization in other cell types or PIN1 polarization. This relocation of cortical PIN2 was negatively regulated by the membrane trafficking factor GNOM and by the regulatory A1 subunit of type 2-A protein phosphatase (PP2AA1) but did not require the PINOID protein kinase. When GNOM was inhibited, PINOID abundance increased and PP2AA1 was partially immobilized, indicating both proteins are subject to GNOM-dependent regulation. Shootward PIN2 specifically in the cortex was accompanied by enhanced shootward polar auxin transport and by diminishedgravitropism. These results demonstrate that auxin flow in the root cortex is important for optimal gravitropic response.
Session 6.Organelle biology A B S T R A C T B O O K – A B S T R A C T S O F T A L K S PEROXISOME DEGRADATION PATHWAYS IN PLANTS Olga V. Voitsekhovskaja 1,2 , Andreas Schiermeyer 3 , Sigrun Reumann 1,4 1 Department of Plant Biochemistry, Georg-August-University of Goettingen, Goettingen, Germany 2 Komarov Botanical Institute, Russian Academy of Sciences, St. Petersburg, Russian Federation 3 Fraunhofer-Institut fürMolekularbiologie und AngewandteOekologie, Aachen, Germany 4 Centre for Organelle Research, University of Stavanger, Stavanger, Norway E-mail: ovoitse@yandex.ru In fungi and mammals, peroxisomes are reported to be degraded by micro- and/or macroautophagy but such knowledge is yet lacking for plants. To study peroxisome degradation pathways in plants, stable transgenic suspension-cultured cell lines of tobacco cv Bright Yellow 2 were generated that expressed a peroxisome-targeted version of enhanced yellow fluorescent protein (EYFP). Autophagy was induced by carbohydrate withdrawal from the culture medium. Biochemical and cytological analyses demonstrated that application of the inhibitor of macroautophagy, 3-methyladenine (3-MA), caused a significant accumulation of EYFP-SKL and native peroxisomal proteins and an increase in cellular peroxisome numbers, indicating that peroxisomes are degraded by macroautophagy. The subcellular localization of peroxisomes was shown to coincide with autolysosomes and autophagic bodies, consistent with the transport of peroxisomes to the vacuole for proteolytic degradation by macroautophagic compartments. Unexpectedly, 3-MA caused a significant accumulation of peroxisomes also under nutrient-rich conditions, demonstrating that plant peroxisomes are turned over by constitutive macroautophagy under standard growth conditions. The rate of peroxisome turnover exceeded that of plastids and mitochondria under both conditions. The results suggest that peroxisomal matrix proteins are prone to oxidative damage even under nonstressed conditions and that specific yet unknown signaling pathways exist for selective degradation of dysfunctional peroxisomes. 32 X X I V S P P S C O N G R E S S 2 0 1 1
Page 1 and 2: ��
Page 3 and 4: Foreword eword ord A B S T R A C T
Page 5 and 6: Program of the Congress gram of the
Page 7 and 8: A B S T R A C T B O O K - P R O G R
Page 9 and 10: A B S T R A C T B O O K - P R O G R
Page 11 and 12: Plenary session 1 A B S T R A C T B
Page 13 and 14: Plenary session 2 THE BIOLOGY OF AL
Page 15 and 16: Session 1. Biotechnology and synthe
Page 17 and 18: Session 1. Biotechnology and synthe
Page 19 and 20: Session 2. Systems biology and -omi
Page 21 and 22: Session 2. Systems biology and -omi
Page 23 and 24: A B S T R A C T B O O K - A B S T R
Page 27 and 28: Pleanary session 4 A B S T R A C T
Page 29 and 30: Invited talk 4 A B S T R A C T B O
Page 31: Session 5.Cell biology A B S T R A
Page 35 and 36: Session 6.Organelle biology A B S T
Page 37 and 38: Session 7.Development A B S T R A C
Page 39 and 40: Session 8.Signalling A B S T R A C
Page 41 and 42: Pleanary session 6 A B S T R A C T
Page 51 and 52: Session 13.Pathogen defense and pla
Page 53 and 54: Session 13.Pathogen defense and pla
Page 67 and 68: Sapporo Medical University, Sapporo
Page 83 and 84:
A B S T R A C T B O O K - A B S T R
Page 85 and 86:
Page 87 and 88:
Page 89 and 90:
Page 91 and 92:
SCF = A B S T R A C T B O O K - A B
Page 93 and 94:
A B S T R A C T B O O K - L I S T O
Page 95 and 96:
A B S T R A C T B O O K - L I S T O
Page 97 and 98:
Sponsors onsors ors A B S T R A C T
show all

1. Front Cover.cdr - CORE

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?