Biology subjects

Clemente, T. E.

Publications and source records attributed to Clemente, T. E..

3 recordsLinked to original sources

bioRxiv2024

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

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.

plant biology↗

bioRxiv2024

Adapting C4 photosynthesis to atmospheric change and increasing productivity by elevating Rubisco content in Sorghum and Sugarcane

Meta-analyses and theory show that with rising atmospheric [CO2], Rubisco has become the greatest limitation to light-saturated leaf CO2 assimilation rates (Asat) in C4 crops. So would transgenically increasing Rubisco increase Asat and result in increased productivity in the field? Here, we successfully overexpressed the Rubisco small subunit (RbcS) with Rubisco accumulation factor 1 (Raf1) in both sorghum and sugarcane, resulting in significant increases in Rubisco content of 13-25% and up to 90% respectively. Asat increased 12-15% and Rubisco enzyme activity [~]40% in three independent transgenic events of both species. Sorghum plants also showed increased speeds of photosynthetic induction and decreased bundle sheath leakiness. These improvements translated into average increases of 15.5% in biomass in field-grown sorghum and a 37-81% increase in greenhouse-grown sugarcane. This suggests a potential opportunity to achieve substantial increases in productivity of this key economically important clade of C4 crops, future proofing their value under global atmospheric change. Significance StatementThe world is projected to need a 60% increase in food supply by 2050 (UN), and this must be achieved under conditions of global change without expanding onto yet more land. C4 crops, while few in number, account for a large proportion of agricultural productivity. We reason that rising atmospheric [CO2] has very recently made Rubisco, the enzyme used for all carbon fixation in plants, the greatest limitation to light saturated photosynthesis in C4 crops. We demonstrate that transgenically increasing Rubisco content in sorghum and sugarcane, increases their photosynthetic efficiency and productivity, including in a field trial of sorghum. This shows a means to sustainably increase the productivity of this key group of crops.

plant biology↗

bioRxiv2020

Development of mPing-based Activation Tags for Crop Insertional Mutagenesis

Modern plant breeding increasingly relies on genomic information to guide crop improvement. Although some genes are characterized, additional tools are needed to effectively identify and characterize genes associated with crop traits. To address this need, the mPing element from rice was modified to serve as an activation tag to induce expression of nearby genes. Embedding promoter sequences in mPing resulted in a decrease in overall transposition rate; however, this effect was negated by using a hyperactive version of mPing called mmPing20. Transgenic soybean events carrying mPing-based activation tags and the appropriate transposase expression cassettes showed evidence of transposition. Expression analysis of a line that contained a heritable insertion of the mmPing20F activation tag indicated that the activation tag induced overexpression of the nearby soybean genes. This represents a significant advance in gene discovery technology as activation tags have the potential to induce more phenotypes than the original mPing element, improving the overall effectiveness of the mutagenesis system.

plant biology↗