Time filter

Source Type

Chakravorty D.,University of Queensland | Chakravorty D.,Pennsylvania State University | Trusov Y.,University of Queensland | Zhang W.,Pennsylvania State University | And 6 more authors.
Plant Journal | Year: 2011

Summary Currently, there are strong inconsistencies in our knowledge of plant heterotrimeric G-proteins that suggest the existence of additional members of the family. We have identified a new Arabidopsis G-protein β-subunit (AGG3) that modulates morphological development and ABA-regulation of stomatal aperture. AGG3 strongly interacts with the Arabidopsis G-protein β-subunit in vivo and in vitro. Most importantly, AGG3-deficient mutants account for all but one of the 'orphan' phenotypes previously unexplained by the two known β-subunits in Arabidopsis. AGG3 has unique characteristics never before observed in plant or animal systems, such as its size (more than twice that of canonical β-subunits) and the presence of a C-terminal Cys-rich domain. AGG3 thus represent a novel class of G-protein β-subunits, widely spread throughout the plant kingdom but not present in animals. Homologues of AGG3 in rice have been identified as important quantitative trait loci for grain size and yield, but due to the atypical nature of the proteins their identity as G-protein subunits was thus far unknown. Our work demonstrates a similar trend in seeds of Arabidopsis agg3 mutants, and implicates G-proteins in such a crucial agronomic trait. The discovery of this highly atypical subunit reinforces the emerging notion that plant and animal G-proteins have distinct as well as shared evolutionary pathways. © 2011 Blackwell Publishing Ltd.


Zhang G.-Z.,Key Laboratory of Plant Cell Engineering and Germplasm Innovation | Jin S.-H.,Qingdao Agricultural University | Jiang X.-Y.,Key Laboratory of Plant Cell Engineering and Germplasm Innovation | Dong R.-R.,Key Laboratory of Plant Cell Engineering and Germplasm Innovation | And 3 more authors.
Plant Molecular Biology | Year: 2016

The formation of auxin glucose conjugate is proposed to be one of the molecular modifications controlling auxin homeostasis. However, the involved mechanisms and relevant physiological significances are largely unknown or poorly understood. In this study, Arabidopsis UGT75D1 was at the first time identified to be an indole-3-butyric acid (IBA) preferring glycosyltransferase. Assessment of enzyme activity and IBA conjugates in transgenic plants ectopically expressing UGT75D1 indicated that the UGT75D1 catalytic specificity was maintained in planta. It was found that the expression pattern of UGT75D1 was specific in germinating seeds. Consistently, we found that transgenic seedlings with over-produced UGT75D1 exhibited smaller cotyledons and cotyledon epidermal cells than the wild type. In addition, UGT75D1 was found to be up-regulated under mannitol, salt and ABA treatments and the over-expression lines were tolerant to osmotic and salt stresses during germination, resulting in an increased germination rate. Quantitative RT-PCR analysis revealed that the mRNA levels of ABA INSENSITIVE3 (ABI3) and ABI5 gene in ABA signaling were substantially down-regulated in the transgenic lines under stress treatments. Interestingly, AUXIN RESPONSE FACTOR 16 (ARF16) gene of transgenic lines was also dramatically down-regulated under the same stress conditions. Since ARF16 functions as an activator of ABI3 transcription, we supposed that UGT75D1 might play a role in stress tolerance during germination through modulating ARF16–ABI3 signaling. Taken together, our work indicated that, serving as the IBA preferring glycosyltransferase but distinct from other auxin glycosyltransferases identified so far, UGT75D1 might be a very important player mediating a crosstalk between cotyledon development and stress tolerance of germination at the early stage of plant growth. © 2015, Springer Science+Business Media Dordrecht.


Dong D.-J.,Key Laboratory of Plant Cell Engineering and Germplasm Innovation | Liu P.-C.,Key Laboratory of Plant Cell Engineering and Germplasm Innovation | Wang J.-X.,Key Laboratory of Plant Cell Engineering and Germplasm Innovation | Zhao X.-F.,Key Laboratory of Plant Cell Engineering and Germplasm Innovation
Amino Acids | Year: 2012

GRIM-19 (genes associated with retinoid-IFNinduced mortality-19) is a subunit of mitochondrial respiratory complex I in mammalian systems. However, its function in vivo is not really understood. We cloned GRIM-19 and explored its function and hormonal regulation in insect, the cotton bollworm, Helicoverpa armigera. The results showed that Ha-GRIM-19 was highly expressed during the larval stage. Its transcript levels could be upregulated by juvenile hormone (JH) analog methoprene or by methoprene plus 20E. The methoprene-upregulated transcription enhancement of Ha- GRIM-19 was mediated by the transcription factor Ha-Met1, the putative receptor of JH. Other transcription factors Ha- USP1 and Ha-Br-Z2 suppressed the action of methoprene in inducing Ha-GRIM-19 expression, but Ha-Br-Z2 introduced interaction between 20E and methoprene in upregulation of Ha-GRIM-19. The knockdown of Ha-GRIM-19 by RNA interference in larvae and in insect cell line induced programmed cell death. These data imply that Ha-GRIM-19 plays role in keeping the normal cellular growth and it is able to be upregulated by methoprene through putative JH receptor Met. © Springer-Verlag 2010.


Wang M.,Key Laboratory of Plant Cell Engineering and Germplasm Innovation | Ma X.,Key Laboratory of Plant Cell Engineering and Germplasm Innovation | Shen J.,Key Laboratory of Plant Cell Engineering and Germplasm Innovation | Li C.,Key Laboratory of Plant Cell Engineering and Germplasm Innovation | Zhang W.,Key Laboratory of Plant Cell Engineering and Germplasm Innovation
Plant Signaling and Behavior | Year: 2014

Abscisic acid (ABA) is an important regulator of guard cell ion channels and stomatal movements in response to drought stress. Pyruvate is the final product of glycolysis in the cytosol, and could be transported by mitochondrial pyruvate carriers (MPCs) into mitochondrion for consequent cellular substance and energy metabolism. We recently characterized the first putative mitochondrial pyruvate carrier, NRGA1, in planta, and found that this small protein is involved in the negative regulation of drought and ABA induced guard cell signaling in Arabidopsis thaliana. The findings revealed a probable link between mitochondrial pyruvate transport and guard cell signaling. It has also been shown that NRGA1 protein product was directed to the mitochondria, and co-expression of MPC1 and NRGA1 functionally complement the absence of a native pyruvate transport protein in yeast. Here, we further demonstrated that MPC1 showed similar sub-cellular localization pattern to NRGA1. Quantitative RT-PCR analysis showed that the transcription of both NRGA1 and MPC1 were induced by pyruvate or ABA, and pyruvate strengthened the ABA induced transcription of these 2 genes. The similarity in subcellular localization and gene expression to ABA strongly suggests that MPC1 may associate with NRGA1 for mitochondrial pyruvate transport and is involved in ABA mediated stomatal movements in Arabidopsis. © 2014 Taylor & Francis Group, LLC.


Zhang K.,Key Laboratory of Plant Cell Engineering and Germplasm Innovation | Zhang K.,Shandong University | Li Y.,Key Laboratory of Plant Cell Engineering and Germplasm Innovation | Li Y.,Shandong University | And 2 more authors.
Journal of Agricultural Science | Year: 2011

In order to study pollen-mediated gene flow in transgenic maize (Zea mays L.) in the Huang-huai-hai region of China, field trials were conducted in Jinan, Shandong Province in 2006 and 2007. The frequencies of gene flow from the donor plots, planted with transgenic maize as a pollen source, to the receptor plots, planted with non-transgenic maize, under different temporal or spatial separations were evaluated. The results showed that the frequency of pollen-mediated gene flow of the als gene from transgenic maize to non-transgenic maize decreased significantly with increasing distance. No gene flow was detected at 300 m. At a distance of 30 m, delaying the planting date of the transgenic maize by 1 week decreased the frequency of gene flow by 70%. A delay of 2 weeks decreased the gene flow frequency by more than 90%, while no gene flow was seen when the sowing date was delayed by 3 weeks. The results suggest that an appropriate isolation distance of 300 m or a temporal separation of 3 weeks could prevent gene flow from transgenic maize to non-transgenic maize in the Huang-huai-hai region. © 2010 Cambridge University Press.

Loading Key Laboratory of Plant Cell Engineering and Germplasm Innovation collaborators
Loading Key Laboratory of Plant Cell Engineering and Germplasm Innovation collaborators