Archive

10 March 2016, Volume 30 Issue 2 Previous Issue    Next Issue
---
Orginal Article


For Selected:

Download Citations EndNote Ris BibTeX

Toggle Thumbnails

Orginal Article

Select

Expression Profiles of Rice WRKY Transcription Factor Gene Family Responsive to Exogenous Nitric Oxide Application Jiao MENG, Hai-hua WANG, Jian-hua XIANG, Dan JIANG, Xi-xu PENG, Huan-huan HE 2016, 30(2): 111-120.  DOI: 10.16819/j.1001-7216.2016.5138 Abstract ( )   HTML ( )   PDF (2100KB) ( )   Signal molecule nitric oxide (NO) and WRKY transcription factors are involved in many physiological processes, such as defense against stresses, development and metabolism in plants. In the present study, we investigated the expression patterns of WRKY transcription factor gene family in rice seedlings at 1, 6 and 12 after exogenous NO treatments using Agilent rice cDNA oligo microarray. Totally, 32 differently expressed WRKY genes, whose expression levels increased or decreased by at least two-fold at one time point compared with the control (T0), were identified. These WRKY genes were mainly distributed over Groups Ⅰ and Ⅱ, among which 75% of Ⅱa and 45.6% of Ⅱd subgroup members were differently expressed upon the NO treatments. Moreover, 15 identified NO-responsive WRKY genes, whose expression level changed by more than two-fold at least two time points among the three time points compared with the control, exhibited an earlier (1 h) response to the NO treatments, and most of them (64.2%) were continually up-regulated. Prediction of gene function revealed that the NO-responsive WRKY genes were mainly involved in cellular process, metabolic process and response to stimulus of biological process, and transcription regulator activity and binding of molecular function. The analysis of metabolic pathways showed that WRKY24 was involved in plant-pathogen interaction pathway. The results of microarray hybridization were largely consistent with those of quantitative real-time PCR, verifying the validity of microarray hybridization. These findings suggest that NO signaling might be involved in the regulatory functions of WRKY transcription factors, and provide a basis for further functional research for these differentially expressed WRKY genes.

Select

Overexpressing Analysis of the Flowering Time Gene OsDTH10 in Rice Ying-ying LI, Wei XIONG, Ting SONG, Zhen-hua CAO, Wei-jiang LUAN 2016, 30(2): 121-126.  DOI: 10.16819/j.1001-7216.2016.5140 Abstract ( )   HTML ( )   PDF (1512KB) ( )   Flowering time (heading date) is an important agronomic trait of crops, and it is closely linked with the yield of crops. To reveal the function of rice flowering time gene OsDTH10 in rice, we constructed an overexpressing vector of OsDTH10 and analyzed the function of OsDTH10 by the reverse genetics. The results showed that the OsDTH10-overexpressing (OsDTH10-OV) transgenic plants displayed a late heading phenotype, suggesting that the overexpression of OsDTH10delayed the heading-date of rice. RT-PCR expression analysis showed that the expression level of OsDTH10was increased obviously in OsDTH10-OV lines with phenotype compared with the transgenic lines without phenotype and wild type plants, indicating that late heading phenotype in OsDTH10-OV lines was caused by the overexpression of OsDTH10. The tissue-specific expression showed that OsDTH10 was expressed in different organs, with the higher expression levels in stem and leaf sheath. Also, we further analyzed the expression of OsDTH10 in leaves at various leaf-ages, and the result showed that OsDTH10 exhibited higher expression in unexpanded flag leaf and the second leaf from the top than these in the third and the fourth leaf from the top. In addition, we also analyzed the expression of OsDTH10 in different photoperiods, and the result indicated that OsDTH10displayed a higher expression during the day time (light stage) and a lower expression at night (dark stage) whatever short-day and long-day conditions, suggesting that OsDTH10 might be involved in the photoperiodic pathways to regulate the heading-date in rice.

Select

Characterization and Gene Mapping of a Dominant Brittle Culm Mutant Bc18 in Rice (Oryza sativa L.) Ying-cai PENG, Wen-zhen LIU, Ya-ping FU, He-tong WANG, Guo-cheng HU, Wen-fu CHEN, Zheng-jin XU 2016, 30(2): 127-135.  DOI: 10.16819/j.1001-7216.2016.5162 Abstract ( )   HTML ( )   PDF (940KB) ( )   A brittle culm mutant was obtained from the F2 population of three-way cross Ⅱ-32B//Xieqingzao B/Dular and named as Brittle culm 18 ( Bc18 ) according to its phenotypes. Each part of plant showed brittleness during the whole growth period. In order to identify the mutant, near isogenic line populations of Zhongcui B and Zhong 9B were created with Bc18 mutant as the donor of brittle gene and Zhong 9B, a normal culm-strength variety, as the receptor and recurrent parent. Compared with wild type, Bc18 significantly declined by 70.70% and 47.16% in mechanical strength of culm and leaves, respectively. No significant differences were found in terms of growth duration, plant height, panicle number per plant, spikelet number per panicle, seed setting rate and 1000-grain weight. Cell wall components analyses showed that cellulose content and lignin content in Bc18 had no significant difference as compared with those of wild type, while hemicellulose content in culm and leaf dramatically increased by 31.84% and 17.35%, respectively. Genetic analyses of six F2 and twelve BC1F1 backcross populations revealed that the phenotype of Bc18 was controlled by a single dominant gene. Bc18/02428 and Bc18/9311 F2 populations were developed for Bc18 gene mapping. By means of map-based cloning technology, with some SSR markers published online and new designed InDel markers, Bc18 was localized between InDel marker PBC22 and PBC33 at a physical distance of about 154 kb on the long arm of chromosome 1. This work laid the foundation for cloning Bc18 gene in the future.

Select

Genetic Analysis and Gene Mapping of an Albino Lethal Mutant in Rice Zhi-zhan CHU, Xiao-lin LIU, Yuan-ling CHEN, Yao-guang LIU 2016, 30(2): 136-142.  DOI: 10.16819/j.1001-7216.2016.5133 Abstract ( )   HTML ( )   PDF (2602KB) ( )   An albino lethal mutant, temporarily termed as al14 (albino 14),was obtained from 60Co γ-ray radiated mutant pool of japonica rice variety Nipponbare. The mutant showed albino phenotype from germination, and died after 3-leaf stage. Genetic analysis revealed that the mutant phenotype was controlled by a single recessive nuclear gene. The chlorophyll and carotenoid contents in al14 declined dramatically. Transmission electron microscopy examination showed there were no obvious chloroplasts except prolamellar bodies in al14. The expression level of most genes of photosystemⅠand photosystem Ⅱdecreased dramatically, but the ribosomal genes and RNA polymerase genes in chloroplast increased notably in al14 mutant. In al14,the expression amount of PsbN, a photosystem Ⅱ protein N gene, was 118.23 times as high as that in wild type. By genetic mapping with an F2 population generated by crossing the heterozygous al14 plants with indica variety Huanghuazhan, the al14 locus was mapped within 40 kb on chromosome 6. So far there is no reported gene relative to leaf color, so it is a novel gene controlling chloroplast development.

Select

Identification and Gene Mapping of Male Sterile Mutant gamyb5 in Rice Zheng-fu YANG, Ying-xin ZHANG, Lian-ping SUN, Pei-pei ZHANG, Dan-dan XUAN, Ling LIU, Xia HU, Zi-he LI, Xiao-deng ZHAN, Wei-xun WU, Li-yong CAO, Shi-hua CHENG 2016, 30(2): 143-151.  DOI: 10.16819/j.1001-7216.2016.5154 Abstract ( )   HTML ( )   PDF (2947KB) ( )   The gamyb5, a pollen-free male sterile mutant was identified from the mutant library of 60Co-γ-treated indica cultivar Zhonghui 8015. There was no significant difference in agronomic traits such as plant type, plant height and tiller number between gamyb5 and the wild-type. But gamyb5 exhibited slender and white anthers without mature pollen grains. Observation results of anther cross-sections exhibited that the microspore mother cells failed to form functional tetrads and microspores in gamyb5. Moreover, tapetal cells of gamyb5 abnormally enlarged and the tapetum programmed cell death (PCD) was delayed. gamyb5, as the pollen acceptor, was crossed with the wild type Zhonghui 8015 and a japonica cultivar 02428, respectively. Genetic analysis of all hybridization populations indicated that gamyb5 was controlled by a single recessive nuclear gene which was mapped on the long arm of chromosome 1. With developed SSR, Indel markers and F2 mapping population of gamyb5/02428, the gene was fine mapped to a region of 16-kb on the long arm of chromosome 1 between markers ZF-29 and ZF-31. Sequence analysis of the two open reading frames in this region revealed that the LOC_Os01g0812000, which encodes a gibberellin-induced MYB transcription factor, had an 8 nucleotides bases deletion in the second extron probably responsible for the male sterility phenotype. Additionally, real-time fluorescent quantitative PCR analysis showed that the expression level of the important regulators UDT1, TDR, CYP703A3 and CYP704B2 in anther decreased significantly in gamyb5. Together, these results suggest GAMYB plays key roles in anther meiosis and tapetum PCD.

Select

Phenotypical Analysis and Fine Mapping of a Semi-dominant Dwarfism Gene Si-dd1 in Rice Yong-tao CUI, Li-wen WU, Shi-kai HU, De-yong REN, Chang-wei GE, Wei-jun YE, Guo-jun DONG, Long-biao GUO, Xing-ming HU 2016, 30(2): 152-160.  DOI: 10.16819/j.1001-7216.2016.5113 Abstract ( )   HTML ( )   PDF (1255KB) ( )   A semi-dominant dwarf rice mutant (termed as Si-dd1) was obtained from japonica rice variety Nipponbare by tissue culture mutagenesis. Morphological analysis showed that Si-dd1(AA) and Si-dd1(Aa) exhibited shorter plant height, decreased seed-setting rate, delayed heading, increased number of primary rachis branch and secondary rachis branch compared to the wild type (WT,Nipponbare). Physiological test results showed Si-dd1 had similar response to 24-Epibrassinosteroid to the WT, while it was insensitive to Gibberellin at 10-4μmol/L. Moreover, Western blot results also confirmed GID2 expression level in Si-dd1 differed greatly from WT. The cytological analysis showed that Si-dd1 had smaller stomas in the leaf midrib, increased mesophyll cells and stem vascular bundles compared to WT. Genetic analysis and map-based clone showed that the Si-dd1 is controlled by a single semi-dominant gene, and locates in a 244 kb region on chromosome 6.

Select

Response of Rice Organ Morphology and Dry Matter Accumulation to High Temperature at Different Panicle Initiation Stages Ya-liang WANG, Yu-ping ZHANG, De-feng ZHU, Jing XIANG, Hui-zhe CHEN, Yi-kai ZHANG 2016, 30(2): 161-169.  DOI: 10.16819/j.1001-7216.2016.5137 Abstract ( )   HTML ( )   PDF (702KB) ( )   A pot experiment in controlled-environment chambers was conducted to determine the effects of high temperature(40℃) on the rice organ morphology and dry matter accumulation during panicle initiation stage. Two mid-indica rice cultivars(Huanghuazhan,heat-tolerant;Fengliangyou 6,heat-sensitive) were planted and exposed to high temperature(40℃,10:00-15:00), and normal temperature(32℃,10:00-15:00) during branch-spikelet differentiation stage(I) and pollen mother cell formation-meiosis stage(Ⅱ), meanwhile rice was grown in ambient conditions as CK. The results indicated that, 1) at stage I high temperature inhibited panicle initiation, extending the panicle initiation stage by 2.5-8.8 d, while at stage Ⅱ,by 6.8-7.1d, which shortened the length of the top internode and reduced the heading degree,especially in Fengliangyou 6. 2)Heat stress at panicle initiation stage significantly decreased the number and the size of spikelets, which might be due to the significant difference in treatment period.High temperature at stage I inhibited spikelet differentiation, while at stageⅡ, heat stress mainly promoted spikelet degeneration,the degeneration rate of the two cultivars were up to 50%, with‘Fengliangyou6’ having a higher ratio. High temperature exposure at stage Ⅱ also significantly declined the size of anther, and the spikelet fertility. 3)High temperature promoted the growth of the top three leaves, especially at stage Ⅱ. Heat stress at the two stages had no significant effect on the leaf photosynthesis and dry matter accumulation of single main stem. Heat stress(40℃) exerted no significant influence on dry matter accumulation of culm, leaves and panicle at stage I, but significantly decreased the dry matter accumulation of culm and panicle at stage Ⅱ, leading to upper-internode tillering and resultant dry matter accumulation.

Select

Plant-type Characteristics of High-Yielding Lines of Yongyou japonica/indica Hybrid Rice with Medium Maturity Tian-yao MENG, Xiao-yun LI, Chao LI, Huan-he WEI, Tian-yu SHI, Rong-rong MA, Xiao-yan WANG, Jun-wen YANG, Qi-gen DAI, Hong-cheng ZHANG 2016, 30(2): 170-180.  DOI: 10.16819/j.1001-7216.2016.5135 Abstract ( )   HTML ( )   PDF (542KB) ( )   A field experiment was conducted using Yongyou japonica/indica hybrids with medium maturity as material, conventional japonica rice (CJR) Ningjing 3 and Wuyunjing 29, hybrid indica rice (HIR) Fengliangyouxiang 1 and Xinliangyou 6380 as the check. Differences in panicle, leaf, and culm traits of various rice types were compared. The results were follows: 1) Yongyou japonica/indica hybrids were divided into two types:high-yielding lines (HYL,over 10.5t/hm2) and medium-yielding lines (MYL,less than 10.5t/hm2) based on yield performance. HYL includes Yongyou 2638, Yongyou 2640, Yongyou 1610, Yongyou 1612, and Yongyou 1640, while MYL includes Yongyou 1851, Yongyou 1852, Yongyou 1763, Yongyou 7753, and Yongyou 5854. CJR had the highest number of panicles, seed-setting rate, and 1000-grain weight, while HYL had the highest spikelet number per panicle. 2) HIR had the longest panicle length, while HYL had the highest grain weight per panicle and grain density. HIR had the highest number of spikelets on the low secondary rachis branches,while HYL and MYL had the highest number of spikelets in other panicle positions, especially on the upper secondary rachis branches and the middle secondary rachis branches of panicle. 3) Leaf length and width of the top-three leaves followed a tendency of MYL>HIR>HYL>CJR. HYL had consistently higher rolling rate of top-three leaves than MYL. HYL had the lowest leaf basic angle and dropping angle of the 1st and 2nd leaf from the top. 4) Plant height of HYL was 118.7 cm, higher than CJR (96.6 cm), shorter than HIR (132.9 cm) and MYL (144.1 cm). MYL had the highest length of top-three nodes, while CJR showed the opposite. HYL had the lowest rate of panicle and neck internode to plant height and rate of neck internode to stalk length, while HYL had the highest dry weight per stem, dry weight per sheath, and dry weight per unit internode among different rice types. Breeding index on plant-type characteristics of high-yielding lines of Yongyou japonica/indica hybrid rice with medium maturity and corresponding cultivation methods were proposed.

Select

Grain Yield and Quality and Physiological and Biochemical Characteristics of Flag Leaf in Early Rice as Affected by Submergence at Filling Stage Jing-hua JI, Zhi-guo HUO, Li-sheng TANG, Yao-dong DU, Fei HU 2016, 30(2): 181-192.  DOI: 10.16819/j.1001-7216.2016.5045 Abstract ( )   HTML ( )   PDF (2497KB) ( )   The early hybrid rice Tianyou 998 and the early conventional rice Guinongzhan were submerged at filling stage to evaluate submergence effects on grain yield, rice quality, and physiological and biochemical characteristics of the flag leaf. The depth of submergence were 2/3, and all of rice plant height lasting 0d,1d,3d,5d and 7d(0 d as CK). The results showed that the plant height increased after submergence and the increments in plant height peaked after 5-7 days of submergence. The grain yield and rice quality decreased significantly after submergence at a depth of 2/3 plant height and complete submergence lasting 1-3 days at the filling stage, especially after complete submergence lasting 5-7 days. The yield decrease was mainly due to reduced effective panicle number after submergence. The grain yield and rice quality varied insignificantly with variety under the same submergence conditions. The free proline and MDA contents in flag leaf increased; however, the SPAD value and the SOD activity decreased following submergence at the filling stage and the variation increased as the depth and duration of submergence increased. The SPAD value and the MDA content, significantly or extremely significantly correlated with grain yield and rice quality at the filling stage, are two physiological indices.

Select

Effects of Nitrogen Fertilizer Application on the Formation of White-belly and White-core as Well as Biochemical Composition of japonica Rice Grains Min XI, Zhao-miao LIN, Yan-ling ZHAO, Xin-cheng ZHANG, Xiao-yu YANG, Zheng-hui LIU, Gang-hua LI, Shao-hua WANG, Yan-feng DING 2016, 30(2): 193-199.  DOI: 10.16819/j.1001-7216.2016.5039 Abstract ( )   HTML ( )   PDF (405KB) ( )   The white-belly and white-core mutants (WBRK and WCRK) from Wuyujing 3 were used to clarify the effects of nitrogen application levels (zero nitrogen application,CK; the ratio of basal N fertilizer to topdressing N fertrlizer for panicle initiation 1:1,N5-5; N fertilizer as basal fertilizer N10-0) on the occurrence of white-belly and white-core grains as well as grain chemical components. The results showed that Nitrogen application significantly increased the percentages of white-belly and white-core grains and the latter was more susceptible to nitrogen application. Averaged across nitrogen treatments, WBRK produced grains with similar chemical composition in comparison with those of control. By contrast, WCRK had higher total starch, amylose and amylopectin contents. Also, nitrogen application improved rice milling quality. Compared to CK, rice grains from WBRK showed significantly elevated contents of storage proteins except for albumin as nitrogen topdressing rate increased, while rice grains from WCRK contained significantly higher levels of protein with no significant changes in protein compositions. Nitrogen topdressing increased the contents of the majority of the 17 amino acids, but decreased histidine and arginine contents especially for WCRK. These findings suggested that nitrogen application exerted a significantly different influence on the occurrence of white-belly and white-core kernels and the accumulation of starch and protein during grain filling, indicating the necessity of various formulated strategies to eliminate white-belly and white-core grains.

Select

Effects of Bt Rice with cry1C and cry2A on the Ecological Generation Fitness of Rice Brown Planthoppers(Nilaparvata lugens) and Whitebacked Planthoppers (Sogatella furcifera) at Various Nitrogen Rates Kai LIU, Ya-jun YANG, Jun-ce TIAN, Yan-hui LU, Hong-xing XU, Xu-song ZHENG, Zhong-xian LV 2016, 30(2): 200-209.  DOI: 10.16819/j.1001-7216.2016.5090 Abstract ( )   HTML ( )   PDF (531KB) ( )   In order to evaluate the effects of Bt rice on the generation fitness of non-target pest at different nitrogen rates, as wall as the potential impact of Bt rice and nitrogen fertilizer levels on non-target pest, the brown plantthopper (BPH) (Nilaparvata lugens) and the whitebacked planthopper (WBPH) (Sogatella furcifera), were successively cultured for four generations on Bt rice, T1C-19 with cry1C and T2A-1 with cry2A , and their parental rice Minghui 63, at nitrogen rates of 0, 100 and 250 kg/hm2. The results indicated that the ecological fitness of the BPH and WBPH was increased with the increasing nitrogen fertilizer level, including shortened nymph developmental duration, enhanced fecundity, prolonged longevity, increased nymph survival rate, female weight, egg hatchability and population growth rate. There were significant differences in rice planthopper nymphal development duration, body weight of female adult, fecundity and population growth rate for four successive generations under different nitrogen rates. Transgenic Bt rice, T1C-19 and T2A-1, had no significant effect on the fitness of BPH and WBPH at the same generations and nitrogen rates, except the BPH fecundity. BPH fecundity on transgenic Bt rice T1C-19 at the nitrogen levels of 100 kg/hm2 and 250 kg/hm2(N) was lower compared with the transgenic Bt rice T2A-1 and its parent Minghui 63 from the first generation to the third generation, but no significant difference was found among varieties at the fourth generation at three nitrogen rates. No significant difference was found on the fitness of BPH and WBPH with the generation increase, between non-transgenic Bt rice and transgenic Bt rice. Therefore, the present study demonstrated that nitrogen fertilizer levels exerted a significant influence on the ecological fitness of the rice planthoppers with the generation increase, while transgenic Bt rice didn't.

Select

Effects of Simulated Microclimate near the Water Surface of Rice Paddies on Growth and Reproduction of Sogatella furcifera During High Temperature Season Kai-long LI, Pin-jun WAN, Feng-xiang LAI, Jia-chun HE, Yu ZHENG, Zhi-tao ZHANG, Guo-wen HU, Qiang FU 2016, 30(2): 210-215.  DOI: 10.16819/j.1001-7216.2016.5164 Abstract ( )   HTML ( )   PDF (413KB) ( )   The white-backed planthopper, Sogatella furcifera (Horváth), is a major pest of rice in China. The outbreaks of S. furcifera in the Yangtze River Valley were affected by natural ecological factors. For example, high temperature (over 35℃) in June and August restricted the outbreaks of planthoppers. However, under high temperature,the microclimate near the water surface of rice paddies where planthoppers inhabited were quite different from that in atmospheric environments. According to those differences, the microclimate near the water surface of rice paddies and atmospheric temperature and humidity were simulated in laboratory. Using constant and fluctuating simulated types, the laboratory experiment was performed to compare their effects on the nymph survival rate, duration of nymph stage, fresh weight of newly emerged adults, adult longevity, female fecundity and egg hatching rate of S. furcifera. Our results revealed that: 1) in case of the microclimate near the water surface of rice paddies, all the biological parameters of S. furcifera had no significant difference between the constant and fluctuating temperature and humidity, and S. furcifera successfully completed the whole life cycle;2) compared to the microclimate near the water surface of rice paddies, atmospheric conditions significantly decreased nymph survival rate, duration of female and male nymph, number of eggs per female and hatching rate, respectively. For example, an important biological parameters, the number of eggs per female reduced by 62.1%. We speculate that the microclimate near the water surface of rice paddies may allow S. furcifera to be immune to the detrimental influence of high temperature in the Yangtze River Valley.

Select

Advances in Molecular Understanding of Rice Lodging Resistance Chang LIU, Lai-geng LI 2016, 30(2): 216-222.  DOI: 10.16819/j.1001-7216.2016.5118 Abstract ( )   HTML ( )   PDF (439KB) ( )   Rice lodging is a serious problem impairing grain yield. Plant stature, culm structure and cell wall components play major roles in shaping rice lodging resistance. Genomic and genetic dissection of rice has generated insightful information into mechanistic elucidation of the rice lodging resistance. Here, we summarize the recent advances in molecular understanding of the lodging resistance in association with rice stature, culm character and chemical composition of cell walls. The knowledge helps to establish new molecular strategies for breeding rice varieties with enhanced lodging resistance properties.