Generation of High-Amylose Rice through CRISPR/Cas9-Mediated Targeted Mutagenesis of Starch Branching Enzymes.
Cereals high in amylose content (AC) and resistant starch (RS) offer potential health benefits. Previous studies using chemical mutagenesis or RNA interference have demonstrated that starch branching enzyme (SBE) plays a major role in determining the fine structure and physical properties of starch. However, it remains a challenge to control starch branching in commercial lines. Here, we use CRISPR/Cas9 technology to generate targeted mutagenesis inSBEIandSBEIIbin rice. The frequencies of obtained homozygous or bi-allelic mutant lines with indels inSBEIandSBEIIbin T0generation were from 26.7 to 40%. Mutations in the homozygous T0lines stably transmitted to the T1generation and those in the bi-allelic lines segregated in a Mendelian fashion. Transgene-free plants carrying only the frame-shifted mutagenesis were recovered in T1generation following segregation. Whereas no obvious differences were observed between thesbeImutants and wild type,sbeIImutants showed higher proportion of long chains presented in debranched amylopectin, significantly increased AC and RS content to as higher as 25.0 and 9.8%, respectively, and thus altered fine structure and nutritional properties of starch. Taken together, our results demonstrated for the first time the feasibility to create high-amylose rice through CRISPR/Cas9-mediated editing ofSBEIIb.
Institute of Crop Sciences (ICS), Chinese Academy of Agricultural Sciences (CAAS) Beijing, China.
Yongwei
Y
Sun
China National Rice Research Institute Hangzhou, China.
Guiai
G
Jiao
Institute of Crop Sciences (ICS), Chinese Academy of Agricultural Sciences (CAAS) Beijing, China.
Zupei
Z
Liu
Institute of Crop Sciences (ICS), Chinese Academy of Agricultural Sciences (CAAS) Beijing, China.
Xin
X
Zhang
Institute of Crop Sciences (ICS), Chinese Academy of Agricultural Sciences (CAAS) Beijing, China.
Jingying
J
Li
Institute of Crop Sciences (ICS), Chinese Academy of Agricultural Sciences (CAAS) Beijing, China.
Xiuping
X
Guo
Institute of Crop Sciences (ICS), Chinese Academy of Agricultural Sciences (CAAS) Beijing, China.
Wenming
W
Du
Institute of Crop Sciences (ICS), Chinese Academy of Agricultural Sciences (CAAS) Beijing, China.
Jinlu
J
Du
Functional and Evolutionary Entomology, Gembloux Agro-bio Tech, University of Liege Gembloux, Belgium.
Frédéric
F
Francis
Section of Cell and Developmental Biology, University of California, San Diego, La Jolla CA, USA.
Yunde
Y
Zhao
Institute of Crop Sciences (ICS), Chinese Academy of Agricultural Sciences (CAAS) Beijing, China.
Lanqin
L
Xia
CRISPR/Cas9; amylose content (AC); genome editing; resistant starch (RS); rice; starch; starch branching enzyme (SBE)