Erect panicle architecture contributes to increased rice production through the improvement of canopy structure

The erect panicle architecture has contributed to the improvement of yield in japonica rice breeding, and recent molecular analysis has revealed the mechanisms involved in individual plant yield increases. However, the population structure is more important in rice production compared with individual plant yield. Our study compared the population canopy structure of a curved panicle variety Sasanishiki (WT) and an erect panicle mutant derived from CRISPR/Cas9 gene editing at the DENSE AND ERECT PANICLE 1 (DEP1) locus. The results showed that more light could reach to the leaves under the panicle in the CRISPR-dep1 population compared with the WT. The canopy of the CRISPR-dep1 population exhibited higher temperature and lower humidity compared with the WT after heading. A subsequent survey showed that the CO2 concentration in the CRISPR-dep1 population was significantly lower than that in the WT population from full heading to 15 days after heading. Moreover, the increase of biomass in the CRISPR-dep1 population was greater than that in the WT. We noticed that the CRISPR-dep1 mutant could achieve higher yield under low fertilization application compared with the WT under high fertilizer application through increased transplant density. These traits could contribute to an agricultural sustainable development strategy. The quality investigation showed that the dep1 allele increased the yield along with imposing a penalty on grain quality. Our study not only elucidated the mechanism of yield improvement in an erect panicle architecture variety from the perspective of population structure optimization but also provides a theoretical basis for supporting cultivation systems with the erect panicle architecture.