Sucrose non-fermenting related protein kinases (SnRKs) play important roles
in plant growth, development, metabolism and resistance to environmental
stresses. The soybean genome has four SnRK1 genes, of which GmSnRK1.1 and
GmSnRK1.2 are predominant and participate in multiple stress response
pathways. To study the role of these genes in response to ABA and alkaline
stresses, a research team from the Northeast Agricultural University in
China used CRISPR-Cas9 to knock out both GmSnRK1.1 and GmSnRK1.2.
Analysis of the genome-edited soybeans showed that both genes were
efficiently knocked out in 48.6% of the resulting hairy roots. The team, led
by Hui Qing Li, also generated control hairy roots that overexpressed
GmSnRK1. The wildtypes, knockout lines, and overexpressing lines were all
treated with abscissic acid for 15 days. Results showed that the growth of
the wildtypes and GmSnRK1-overexpressing roots were significantly inhibited
compared to the double-knockout roots. The overexpressing roots also notably
displayed less root lengths and fresh weights.
However, after treatment with sodium bicarbonate for 15 days, the growth of
the double-knockout roots were significantly inhibited compared to the
wildtype and GmSnRK1 overexpressed control roots. These results imply that
knockout of GmSnRK1.1 and GmSnRK1.2 improved hairy root sensitivity to ABA
but also lessened its resistance to alkaline stress.