TY  - JOUR
A1  - Jiang, Fan
A1  - Chen, Lin
A1  - Belimov, Andrey A.
A1  - Shaposhnikov, Alexander I.
A1  - Gong, Fan
A1  - Meng, Xu
A1  - Hartung, Wolfram
A1  - Jeschke, Dieter W.
A1  - Davies, William J.
A1  - Dodd, Ian C.
T1  - Multiple impacts of the plant growth-promoting rhizobacterium Variovorax paradoxus 5C-2 on nutrient and ABA relations of Pisum sativum
JF  - Journal of Experimental Botany
N2  - Resolving the physiological mechanisms by which rhizobacteria enhance plant growth is difficult, since many such bacteria contain multiple plant growth-promoting properties. To understand further how the 1-aminocyclopropane-1-carboxylate (ACC) deaminase (ACCd)-containing rhizobacterium Variovorax paradoxus 5C-2 affects plant growth, the flows and partitioning of mineral nutrients and abscisic acid (ABA) and ABA metabolism were studied in pea (Pisum sativum) plants following rhizosphere bacterial inoculation. Although root architecture was not affected, inoculation increased root and shoot biomass, and stomatal conductance, by 20, 15, and 24%, respectively, and increased N, P, K, Ca, and Mg uptake by 16, 81, 50, 46, and 58%, respectively. P deposition in inoculated plant roots was 4.9 times higher than that in uninoculated controls. Rhizobacterial inoculation increased root to shoot xylem flows and shoot to root phloem flows of K by 1.8- and 2.1-fold, respectively. In control plants, major sinks for K deposition were the roots and upper shoot (43% and 49% of total uptake, respectively), while rhizobacterial inoculation increased K distribution to the lower shoot at the expense of other compartments (xylem, phloem, and upper shoot). Despite being unable to metabolize ABA in vitro, V. paradoxus 5C-2 decreased root ABA concentrations and accumulation by 40–60%. Although inoculation decreased xylem ABA flows, phloem ABA flows increased. Whether bacterial ACCd attenuates root to shoot ABA signalling requires further investigation, since ABA is critical to maintain growth of droughted plants, and ACCd-containing organisms have been advocated as a means of minimizing growth inhibition of plants in drying soil.
KW  - Variovorax paradoxus
KW  - abscisic acid
KW  - ACC deaminase
KW  - hormone flow modelling
KW  - nutrient uptake
KW  - pea
KW  - plant–microbe interaction
KW  - rhizobacteria
Y1  - 2012
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-127011
VL  - 63
IS  - 18
ER  - 
TY  - JOUR
A1  - Hyun, Tae Kyung
A1  - van der Graaff, Eric
A1  - Albacete, Alfonso
A1  - Eom, Seung Hee
A1  - Grosskinsky, Dominik K.
A1  - Böhm, Hannah
A1  - Janschek, Ursula
A1  - Rim, Yeonggil
A1  - Ali, Walid Wahid
A1  - Kim, Soo Young
A1  - Roitsch, Thomas
T1  - The Arabidopsis PLAT Domain Protein1 is Critically Involved in Abiotic Stress Tolerance
JF  - PLOS ONE
N2  - Despite the completion of the Arabidopsis genome sequence, for only a relatively low percentage of the encoded proteins experimental evidence concerning their function is available. Plant proteins that harbour a single PLAT (Polycystin, Lipoxygenase, Alpha-toxin and Triacylglycerol lipase) domain and belong to the PLAT-plant-stress protein family are ubiquitously present in monocot and dicots. However, the function of PLAT-plant-stress proteins is still poorly understood. Therefore, we have assessed the function of the uncharacterised Arabidopsis PLAT-plant-stress family members through a combination of functional genetic and physiological approaches. PLAT1 overexpression conferred increased abiotic stress tolerance, including cold, drought and salt stress, while loss-of-function resulted in opposite effects on abiotic stress tolerance. Strikingly, PLAT1 promoted growth under non-stressed conditions. Abiotic stress treatments induced PLAT1 expression and caused expansion of its expression domain. The ABF/ABRE transcription factors, which are positive mediators of abscisic acid signalling, activate PLAT1 promoter activity in transactivation assays and directly bind to the ABRE elements located in this promoter in electrophoretic mobility shift assays. This suggests that PLAT1 represents a novel downstream target of the abscisic acid signalling pathway. Thus, we showed that PLAT1 critically functions as positive regulator of abiotic stress tolerance, but also is involved in regulating plant growth, and thereby assigned a function to this previously uncharacterised PLAT domain protein. The functional data obtained for PLAT1 support that PLAT-plant-stress proteins in general could be promising targets for improving abiotic stress tolerance without yield penalty.
KW  - salicylic acid
KW  - gene expression
KW  - signal transduction
KW  - cold stress
KW  - salt stress
KW  - abscisic acid
KW  - endoplasmatic reticulum
KW  - transcription factors
KW  - pseudomonas syringae
KW  - plants response
Y1  - 2014
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-114648
VL  - 9
IS  - 11
ER  -