我有下表：
V1 V14
1: sp0000001-mRNA-1
2: sp0000001-mRNA-2
3: sp0000001-mRNA-3
4: sp0000005-mRNA-1 GO:0003723
5: sp0000006-mRNA-2 GO:0016021
6: sp0000006-mRNA-1 GO:0016021
我希望从第一列中删除-mRNA-x。如何将strtrim(a,9)应用于每一列？