Effects of exogenous Brassinosteroids on REVEILLE 7-like gene expression in winter wheat under low temperature stress postprint

Abstract: Dongnong Dongmai No.1 (Dn1) is the first strong cold-resistant variety that can be
planted in a large area in the cold zone, and the greening rate is over 85%. To explore the function
of the REVEILLE 7-like gene in winter wheat and the effect of exogenous brassinolide (BR) on the
expression of this gene under low temperature stress. In this study, the cDNA sequence of
REVEILLE 7-like gene of winter wheat (Dn1) was cloned by RT-PCR, and its bioinformatics
analysis was carried out. At the three-leaf stage of winter wheat, BR was sprayed on the leaves, and the leaves and tillers of winter wheat were sampled at 4, 0, -10, -25 ℃. The expression
patterns of this gene in the leaves and tillers of winter wheat in the above different treatment
groups were analyzed by qRT-PCR. The results were as follows: ( 1 ) REVEILLES belonged to
MYB transcription factor family, and the full length of REVEILLE 7-like gene was 1 251 bp,
which encoded 416 amino acids. The encoded protein was an unstable hydrophilic protein, mainly
located in the nucleus. ( 2 ) REVEILLE 7-like had the closest genetic relationship with Aegilops
tauschii and Eremmer wheat, and the total similarity of protein sequence was 78.62%. ( 3 )
REVEILLE 7-like gene promoter contained cis-acting elements involved in adversity response,
hormone response and MYB binding site. ( 4 ) The expression pattern analysis showed that the
expression level of REVEILLE 7-like gene in the control group was significantly higher at 0℃,
-10℃ and -25℃ than at 4℃, suggesting that the gene might play an important role in winter
wheat under low temperature stress. At -10℃ and -25℃, the expression of the gene in leaves and
tillering nodes of winter wheat treated with BR was significantly higher than that of the control
group, and the expression of the gene in tillering nodes treated with BR was significantly higher
than that in leaves. Therefore, when winter wheat was subjected to low temperature stress, BR
could improve the expression of the gene and further improve the cold tolerance of winter wheat,
and with the decrease of temperature, the promotion of cold tolerance of winter wheat tillering
nodes was more significant.