-
Feng Liu,
Yulong Ren,
Yihua Wang, Cheng Peng,
Kunneng Zhou,
Jia Lv,
Xiuping Guo,
Xin Zhang,
Mingsheng Zhong,
Shaolu Zhao,
Ling Jiang,
Haiyang Wang,
Yiqun Bao,
Jianmin Wan
[show abstract]
[hide abstract]
ABSTRACT: In the rice endosperm cells, glutelins are synthesized on rough endoplasmic reticulum as proglutelins and are sorted to the protein storage vacuoles (PSVs) called protein body IIs (PBIIs), where they are converted to the mature forms. Dense vesicle (DV) mediated trafficking of proglutelins in rice seeds has been proposed, but the post-Golgi control of this process is largely unknown. Whether DV can fuse directly with PSV is another matter of debate. In this study, we proposed a regulatory mechanism underlying DV-mediated, post-Golgi proglutelin trafficking to PBII (PSV). gpa2, a loss of function mutant of OsVPS9A, which encodes a GEF of OsRAB5A, accumulated uncleaved proglutelins. Proglutelins were mis-targeted to the paramural bodies, and to the apoplast along the cell wall in the form of DVs, which led to a concomitant reduction of PBII size. Previously reported gpa1, mutated in OsRab5a, has a similar phenotype, while gpa1 gpa2 double mutant exacerbated the conditions. In addition, OsVPS9A interacted with OsRAB5A in vitro and in vivo. We concluded that OsVPS9A and OsRAB5A may work together and play a regulatory role in DV-mediated post-Golgi proglutelin trafficking to PBII (PSV). The evidences that DVs might fuse directly to PBII (PSV) to deliver cargos were also presented.
Molecular Plant 05/2013; · 5.55 Impact Factor
-
Kunneng Zhou,
Yulong Ren,
Jia Lv,
Yihua Wang,
Feng Liu,
Feng Zhou,
Shaolu Zhao,
Saihua Chen, Cheng Peng,
Xin Zhang,
Xiuping Guo,
Zhijun Cheng,
Jiulin Wang,
Fuqing Wu,
Ling Jiang,
Jianmin Wan
[show abstract]
[hide abstract]
ABSTRACT: Chlorophyll (Chl) and lutein are the two most abundant and essential components in photosynthetic apparatus, and play critical roles in plant development. In this study, we characterized a rice mutant named young leaf chlorosis 1 (ylc1) from a (60)Co-irradiated population. Young leaves of the ylc1 mutant showed decreased levels of Chl and lutein compared to those of wild type, and transmission electron microscopy analysis revealed that the thylakoid lamellar structures were obviously loosely arranged. Whereas, the mutant turns green gradually and approaches normal green at the maximum tillering stage. The Young Leaf Chlorosis 1 (YLC1) gene was isolated via map-based cloning and identified to encode a protein of unknown function belonging to the DUF3353 superfamily. Complementation and RNA-interference tests confirmed the role of the YLC1 gene, which expressed in all tested rice tissues, especially in the leaves. Real-time PCR analyses showed that the expression levels of the genes associated with Chl biosynthesis and photosynthesis were affected in ylc1 mutant at different temperatures. In rice protoplasts, the YLC1 protein displayed a typical chloroplast location pattern. The N-terminal 50 amino acid residues were confirmed to be necessary and sufficient for chloroplast targeting. These data suggested that the YLC1 protein may be involved in Chl and lutein accumulation and chloroplast development at early leaf development in rice.
Planta 09/2012; · 3.00 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: To quantitatively characterize interfractional anatomic variations in pancreatic cancer radiotherapy (RT) and to study dosimetric advantages for using an online adaptive replanning scheme to account for these variations.
Targets and organs at risk (OAR) were delineated by autosegmentation based on daily computed tomography (CT) images acquired using a respiration-gated in-room CT during daily image-guided RT (IGRT) for 10 pancreatic cancer patients. Various parameters, including the maximum overlap ratio (MOR) between the volumes based on planning and daily CTs for a structure, while the overlapping volumes were maximized, were used to quantify the interfractional organ deformation with the intrafractional variations largely excluded. An online adaptive RT (ART) was applied to these daily CTs. To evaluate the dosimetric benefits of ART, the dose distributions from the online ART were compared to those from the repositioning in the current standard IGRT practice.
The interfractional anatomic variations, particularly the organ deformation, are significant during pancreas irradiation. For the patients studied, the average MORs of all daily CTs were 80.2%, 61.7%, and 72.2% for pancreatic head, duodenum, and stomach, respectively. The online ART leads to improved dosimetric plan with better target coverage and/or OAR sparing than IGRT repositioning. For the patients studied, the mean V(50.4 Gy) (volume covered by 50.4 Gy) for the duodenum was reduced from 43.4% for IGRT to 15.6% for the online ART scheme.
The online adaptive RT scheme can effectively account for the significant interfractional anatomic variations observed in pancreas irradiation. The dosimetric advantages with the online ART may enable safe dose escalation in radiation therapy for pancreatic cancer.
International journal of radiation oncology, biology, physics 03/2012; 83(3):e423-9. · 4.59 Impact Factor
-
Xiaohua Han,
Yihua Wang,
Xi Liu,
Ling Jiang,
Yulong Ren,
Feng Liu, Cheng Peng,
Jingjing Li,
Ximing Jin,
Fuqing Wu,
Jiulin Wang,
Xiuping Guo,
Xin Zhang,
Zhijun Cheng,
Jianmin Wan
[show abstract]
[hide abstract]
ABSTRACT: The rice somaclonal mutant T3612 produces small grains with a floury endosperm, caused by the loose packing of starch granules. The positional cloning of the mutation revealed a deletion in a gene encoding a protein disulphide isomerase-like enzyme (PDIL1-1). In the wild type, PDIL1-1 was expressed throughout the plant, but most intensely in the developing grain. In T3612, its expression was abolished, resulting in a decrease in the activity of plastidial phosphorylase and pullulanase, and an increase in that of soluble starch synthase I and ADP-glucose pyrophosphorylase. The amylopectin in the T3612 endosperm showed an increase in chains with a degree of polymerization 8-13 compared with the wild type. The expression in the mutant's endosperm of certain endoplasmic reticulum stress-responsive genes was noticeably elevated. PDIL1-1 appears to play an important role in starch synthesis. Its absence is associated with endoplasmic reticulum stress in the endosperm, which is likely to underlie the formation of the floury endosperm in the T3612 mutant.
Journal of Experimental Botany 01/2012; 63(1):121-30. · 5.36 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: A collection of 515 rice landraces originating from Vietnam and China were screened for the reaction to brown planthopper (BPH) infestation. Most of the resistant landraces were indica types from Vietnam and the Guangxi province in China. An F(2) mapping population was created from the cross between a BPH resistant Vietnamese landrace Yagyaw and the susceptible cultivar Cpslo17. Four quantitative trait loci (QTL) contributing to BPH resistance were mapped on chromosomes 2, 4, 7 and 9, respectively. The individual QTL accounted 5.64% to 12.77% of the phenotypic variance, and three resistant alleles were harbored in the resistant landrace Yagyaw. Two QTL located on chromosomes 2 and 4 were identified with significant additive effects and are useful in breeding new rice inbred lines. One resistant allele was harbored by the susceptible parent Cpslo17. This gene is important in selecting rice inbred lines with stronger resistances to BPH.
Hereditas 06/2009; 146(2):67-73. · 0.79 Impact Factor
