Isolation and characterization of a G protein γ subunit gene responsive to plant hormones and abiotic stresses in Brassica napus L

Early maturity is a major objective of oilseed rape (Brassica napus L.) breeding programs in western Canada. Maturity of crops is influenced by time of initiation and flowering. The presence of a vernalization requirement affects plant development by delaying floral initiation until the cold requirement of the plant has been satisfied. Five spring oilseed rape cultivars were screened for their response to vernalization. Vernalization treatments consisted of exposure of germinated seeds to 0–42 d at 4 °C. Plants were assessed under a 20-h photoperiod. In general, there was a cumulative response to vernalization, with a decrease in days to each developmental stage as exposure to 4 °C was increased. Vernalization treatment of 6 d at 4 °C was sufficient to decrease both the days to first flower and the final leaf number. The characterization of vernalization response is of interest because variation in flowering time in response to year-to-year variations in the environment could result. Key words:Brassica napus, canola, oilseed rape, vernalization

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Inheritance and Molecular Characterization of a Novel Mutated AHAS Gene Responsible for the Resistance of AHAS-Inhibiting Herbicides in Rapeseed (Brassica napus L.)

International Journal of Molecular Sciences ◽

10.3390/ijms21041345 ◽

2020 ◽

Vol 21 (4) ◽

pp. 1345

Author(s):

Qianxin Huang ◽

Jinyang Lv ◽

Yanyan Sun ◽

Hongmei Wang ◽

Yuan Guo ◽

...

Keyword(s):

Brassica Napus ◽

Molecular Characterization ◽

Herbicide Resistance ◽

Acetohydroxyacid Synthase ◽

Cross Resistance ◽

Single Point Mutation ◽

Wild Type ◽

Brassica Napus L ◽

Herbicide Resistant

The use of herbicides is an effective and economic way to control weeds, but their availability for rapeseed is limited due to the shortage of herbicide-resistant cultivars in China. The single-point mutation in the acetohydroxyacid synthase (AHAS) gene can lead to AHAS-inhibiting herbicide resistance. In this study, the inheritance and molecular characterization of the tribenuron-methyl (TBM)-resistant rapeseed (Brassica napus L.) mutant, K5, are performed. Results indicated that TBM-resistance of K5 was controlled by one dominant allele at a single nuclear gene locus. The novel substitution of cytosine with thymine at position 544 in BnAHAS1 was identified in K5, leading to the alteration of proline with serine at position 182 in BnAHAS1. The TBM-resistance of K5 was approximately 100 times that of its wild-type ZS9, and K5 also showed cross-resistance to bensufuron-methyl and monosulfuron-ester sodium. The BnAHAS1544T transgenic Arabidopsis exhibited higher TBM-resistance than that of its wild-type, which confirmed that BnAHAS1544T was responsible for the herbicide resistance of K5. Simultaneously, an allele-specific marker was developed to quickly distinguish the heterozygous and homozygous mutated alleles BnAHAS1544T. In addition, a method for the fast screening of TBM-resistant plants at the cotyledon stage was developed. Our research identified and molecularly characterized one novel mutative AHAS allele in B. napus and laid a foundation for developing herbicide-resistant rapeseed cultivars.

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