Stability of PAC(Psy-2A-Crt I) gene and agronomic traits in the F_(2:3) of IR36/PAC transgenic plants

This study was carried out to evaluate the expression of yellow endosperm color in the progeny of Psy-2A-Crt I（β-carotene gene, PAC） transgenic plants crossed with IR36. The selected 25 lines of F2 progeny exhibited stable expression of yellow endosperm color and high agronomic characteristics. IR36 and PAC transgenic plant of the grain length, width and ratio showed the same tendency of normal distribution. For progeny selection, colorimeters were as employed to distinguish differing visible colors. Correlation analysis was conducted to investigate the relationship between b＊ value and the expression of specific genes. b＊ value was associated with the relative expression of the PAC-Rev and MAR product by real-time PCR and t-test revealed significant difference. Based on this study, correlation between colorimetric values and real-time PCR was effective to detect gene expression. Yellow endosperm progenies represent a new genetic pool that might be useful to increase the genetic diversity of yellow endosperm rice.

Development and application of plant transformation techniques

Genetic transformation is a powerful biotechnology for introducing novel genes into economically important plants from distantly-related plants or even unrelated species such as microbes and animals.This feat is impossible to be achieved by conventional breeding techniques.Development of transgenic plants has been a controversial subject since 1971 when the first genetically modified organism（GMO）was developed（James and Krattiger1996）.

Expression profiling of transgenes(Cry1Ac and Cry2A) in cotton genotypes under different genetic backgrounds

Transgenic cotton carrying the CrylAc gene has revolutionized insect pest control since its adoption,although the development of resistance in insect pests has reduced its efficacy.After 10 years of cultivating Bacillus thuringiensis(Bt)cotton with a single Cry1 Ac gene,growers are on the verge of adopting Bt cotton that carries the double gene(Cry1 Ac+Cry2 A)due to its better effectiveness against insect pests.Thus,the current study was designed to evaluate the role of each gene in the effectiveness of Bt cotton carrying the double gene.The expression levels of the Cry1 Ac and Cry2 A genes were evaluated in the leaves of 10 genotypes(2 parents and 8 Fhybrids)at 30 days after sowing(DAS),while samples of leaves,bolls and flowers were taken from the upper and lower canopies at 70 and 110 DAS.The Fhybrids were developed through reciprocal crosses between two Bt(CKC-1,CKC-2)and two non-Bt(MNH-786,FH-942)parents.The differential expression of transgenes was evaluated through Enzyme Linked Immuno-Sorbent Assay(ELISA).The results showed that the MNH786 xCKC-1 hybrid had the highest concentrations of Cry1 Ac gene at30 DAS(3.08μg g^(-1))and 110 DAS(1.01μg g^(-1))in leaves.In contrast,the CKC-2 xMNH-786 hybrid showed the lowest concentrations of Cry1 Ac gene at 30 DAS(2.30μg g^(-1))and 110 DAS(0.86μg g^(-1)).The Fhybrid FH-942×CKC-2 showed the highest concentrations of Cry2 A gene at 30 DAS(8.39μg g^(-1))and 110 DAS(7.74μg g^(-1))in leaves,while the CKC-1 xMNH-786 hybrid expressed the lowest concentrations of Cry2 A gene at 30 DAS(7.10μg g^(-1))and 110 DAS(8.31μg g^(-1)).A comparison between the two stages of plant growth showed that leaves had the highest concentrations at 30 DAS,whereas the lowest concentrations were observed at 110 DAS for both genes in leaves.When the expression pattern was compared between various plant parts in genotype CKC-2,it was found that leaves had higher concentrations of Cry1 Ac(3.12μg g^(-1))and Cry2 A(8.31μg g^(-1))at 70 DAS,followed by bolls(Cry1 Ac(1.66μg g^(-1))and Cry2 A(8.15μg g^(-1)))and flowers(Cry1 Ac(1.07μg g^(-1))and Cry2 A(7.99μg g^(-1))).The genotype CKC-2 had higher concentrations of Cry1 Ac(3.12μg g^(-1))and Cry2 A(8.31μg g^(-1))in the upper canopy but less accumulation(2.66μg g^(-1)of Cry1 Ac,8.09μg g^(-1)of Cry2 A)in the lower canopy at 70 DAS.Similarly,at 110 DAS,the expression levels of Cry1 Ac and Cry2 A in upper and lower canopy leaves were 1.52 and 7.92μg 9,and 0.99 and 7.54μg 9,respectively.Hence,the current study demonstrates that different genotypes showed variable expression for both of the Cry1 Ac and Cry2 A genes during plant growth due to different genetic backgrounds.The Cry2 A gene had three-fold higher expression than Cry1 Ac with significant differences in expression in different plant parts.The findings of this study will be helpful for breeding insect-resistant double-gene genotypes with better gene expression levels of Cry1 Ac and Cry2 A for sustainable cotton production worldwide.

A Study on the Sensibility of Embryogenic Suspension Cells of Anthurium andraeanum to Two Antibiotics

In this study,embryogenic cell aggregates obtained from the established embryogenic cell suspension culture system of Anthurium andraeanum‘Alabama’were used as experimental materials to investigate the effects of kanamycin and hygromycin on survival rate of cell aggregates,somatic embryogenesis and plantlet regeneration of A.andraeanum.According to the results,at the embryonic cell propagation stage,lethal doses of kanamycin and hygromycin to embryogenic cell aggregates of A.andraeanum were 200 and 60 mg/L,respectively;at the differentiation stage,either 150 mg/L kanamycin or 40 mg/L hygromycin could inhibit somatic embryogenesis;either 100 mg/L kanamycin or 20 mg/L hygromycin could inhibit plantlet regeneration.These results provided important reference for further studies of transgenic A.andraeanum.

Deoxynivalenol accumulation and detoxification in cereals and its potential role in wheat-Fusarium graminearum interactions

Deoxynivalenol(DON)is a prominent mycotoxin showing significant accumulation in cereal plants during infection by the phytopathogen Fusarium graminearum.It is a virulence factor that is important in the spread of F.graminearum within cereal heads,and it causes serious yield losses and significant contamination of cereal grains.In recent decades,genetic and genomic studies have facilitated the characterization of the molecular pathways of DON biosynthesis in F.graminearum and the environmental factors that influence DON accumulation.In addition,diverse scab resistance traits related to the repression of DON accumulation in plants have been identified,and experimental studies of wheat–pathogen interactions have contributed to understanding detoxification mechanisms in host plants.The present review illustrates and summarizes the molecular networks of DON mycotoxin production in F.graminearum and the methods of DON detoxification in plants based on the current literature,which provides molecular targets for crop improvement programs.This review also comprehensively discusses recent advances and challenges related to genetic engineering-mediated cultivar improvements to strengthen scab resistance.Furthermore,ongoing advancements in genetic engineering will enable the application of these molecular targets to develop more scab-resistant wheat cultivars with DON detoxification traits.