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ABSTRACT: In Arabidopsis, Arabidillo-1 and Arabidillo-2 have great sequence homology to Dictyostelium and metazoan β–catenin/Armadillo, which are important to animal and Dictyostelium development. Arabidillo-1 and Arabidillo-2 promote lateral root formation redundantly in Arabidopsis. Here, we showed that gibberellins (GA3) has a greater inhibitory effect on lateral root growth from the null mutant arabidillo-1 than from the wild type, suggesting that the mechanism for Arabidillo-1-regulated modulation of lateral root proliferation
is associated with GA3-metabolic or signaling pathways. Our yeast two-hybrid analysis demonstrated that Arabidillo-1 interacts with ASK2 and ASK11,
and that ASK2 can bind with the F-box domain of Arabidillo-1. Therefore, Arabidillo-1 is involved in the ubiquitin/26S proteasome-mediated
proteolytic pathway. Based on these results, we conclude that Arabidillo-1 can degrade some positive regulator of the GA3 signaling pathway through selective protein degradation of ubiquitin/26S. Moreover, that process is believed to be the mechanism
for Arabidillo-1 promotion of lateral root development in Arabidopsis.
KeywordsArabidillo-1-Armadillo-F-box-GA-Lateral roots
Journal of Plant Biology 04/2012; 53(5):374-380. · 1.07 Impact Factor
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ABSTRACT: Arabidopsis is a species that naturally displays the rosette form. Therefore, elucidation of the factors, which control basal leaf development,
is of particular interest. Most evidence points that auxins and gibberellins are important in the control of rosette leaf
development. In this paper, we report on a regimen that disrupts the normal rosette growth in Arabidopsis and induces internodal growth, which we have termed unbasal. The growth conditions are: (1) seed germination in the presence
of 2,3,5-triiodobenzoic acid (TIBA); (2) transfer of the seedlings to a medium containing exogenous auxin (NAA) and GA3; (3) transfer of the seedlings to a GA3-only medium for all subsequent growth. Under these conditions, auxin and GA interact to induce internode elongation. Polar
auxin transport appears to have a temporal effect on this synergistic interaction. In this regimen, GA increases auxin activity
in the basal portions of the stem. Cross sectional morphology of the elongated internodes between two rosette leaves in an
un-basal plant was similar to that seen for the pin1 Arabidopsis mutation.
KeywordsArabidopsis-auxin-auxin transport inhibitors-basal growth of rosette leaves-GA-polar auxin transport
Russian Journal of Plant Physiology 04/2012; 57(6):815-825. · 0.71 Impact Factor
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ABSTRACT: Plant meiotic prophase I is a complicated process involving the late zygotene and pachytene stages, both crucial for completing synapsis and recombination. Using David Lily (Lilium davidii var. Willmottiae) as our research material, we performed suppression subtractive hybridization to construct EST library of anthers at various stages of development by the pollen mother cells. From this library, we identified small heat shock protein LimHSP16.45 was highly expressed during the late zygotene to pachytene stages. Our results also showed that LimHSP16.45 was almost specifically expressed in the anther compared with the root, stem, or leaf, and in situ expression of LimHSP16.45 mRNAs showed strong signals in the pollen mother cells and tapetal cells. LimHSP16.45 could be induced by heat and cold in lily anthers, and its ectopic expression enhanced the viability of E. coli cells under both high and low temperatures. In vitro, it acted as molecular chaperone and could help luciferase refolding after heat shock stress. All of these data suggest that LimHSP16.45, working as molecular chaperone, possibly protects pollen mother cells and tapetal cells against extreme temperatures during late zygotene to pachytene stages of meiotic prophase I in David Lily.
Plant Cell Reports 06/2011; 30(10):1981-9. · 2.27 Impact Factor
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Journal of Colloid and Interface Science 340(1):93-97. · 3.07 Impact Factor
