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bioRxiv · 10.1101/2024.12.13.624727

Nitrogen response and growth trajectory of sorghum CRISPR-Cas9 mutants using high-throughput phenotyping

Jin, H.·Park, A.·Sreedasyam, A.·Li, G.·Ge, Y.·Swaminathan, K.·Schmutz, J.·Clemente, T. E.·Schnable, J. C.·Yang, J.
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Abstract

Inorganic nitrogen (N) fertilizer has emerged as one of the key factors driving increased crop yields in the past several decades; however, the overuse of chemical N fertilizer has led to severe ecological and environmental burdens. Understanding how crops respond to N fertilizer has become a central topic in plant science and plant genetics, with the ultimate goal of enhancing N use efficiency (NUE) in crop production. As one of the most essential macronutrients, N significantly influences crop performance across different developmental stages of plant, phenotypic traits result from the accumulative effects of genetic factors, prevailing environmental conditions (specifically N availability), and their complex interactions. To characterize the targeting N-responsiveness and growth trajectory, we employed CRISPR-Cas9 technique to generate sorghum mutants using CRISPR technology. Using a LemnaTec plant imaging system, we obtained time series imagery data from 29 to 130 days after sowing (DAS) for these CRISPR-edited mutants under high N and low N greenhouse conditions. After imagery data analysis, we extracted a number of morphological and greenness index traits as a proxy of plant growth and N responses. Subsequently, we employed two different methods to model the temporal N-responsive traits, allowing us to estimate seven key parameters from the growth curve. Our findings revealed that the wildtype and the edited sorghum lines exhibited differences in N responses for several of the key growth-related parameters. The high-throughput N phenotyping pipeline paves the way for a better understanding of the N responses of edited lines in a dynamic manner and sheds light on further improvements in crop NUE.

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Jin, H., Park, A., Sreedasyam, A., Li, G., Ge, Y., Swaminathan, K., Schmutz, J., Clemente, T. E., Schnable, J. C., Yang, J.. 2024-12-15. Nitrogen response and growth trajectory of sorghum CRISPR-Cas9 mutants using high-throughput phenotyping. https://doi.org/10.1101/2024.12.13.624727

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