Targeting Improved Cotton Through Orbital Cultivation (TICTOC): Overexpression of Arabidopsis Vacuolar H+-Pyrophosphatase (AVP1) regulates spaceflight-induced stress responses in cotton.

Abstract Description:

Cotton, a leading widely grown non-food crop, faces substantial environmental challenges due to its high-water requirements. Previous studies demonstrate that increased expression of the Arabidopsis Vacuolar Pyrophosphatase gene, AVP1, significantly enhances drought and salt tolerance in transgenic plants by boosting proton pump activity and improving water and nutrient absorption through larger root systems, leading to at least a 20% increase in fiber yield in dry-land conditions. Roots play a critical role in water uptake, nutrient utilization, and soil carbon sequestration, which are essential for cotton productivity and stress resilience and are further significantly influenced by gravity's impact on shaping root architecture.

 

The TICTOC experiment aims to identify environmental factors and gene networks controlling root development related to plant resilience, water-use efficiency, and carbon sequestration in spaceflight. During the experiment, wild-type and two varieties of AVP1-overexpressing cotton seeds (AVP1-OX) were germinated and grown for six days in the Veggie growth chamber onboard the International Space Station (ISS). Daily photographs monitored the plant’s growth, along with a parallel ground control experiment run at the Kennedy Space Center’s ISS growth chamber to compare plant growth patterns and gene expression between Earth and space-grown cotton seedlings.

 

Using a variety of approaches, including phenotypic (image analysis), biochemical (pigment and stress marker analysis), glycomics (cell wall remodeling analysis), and transcriptomics (changes at the molecular level analysis) assays, we explore how AVP1-OX regulates plant growth under spaceflight-induced stress conditions. Our findings reveal that AVP1-OX lines displayed more extensive root growth than wild-type plants in both flight and ground controls. Biochemical analyses indicated reduced oxidative stress and stable photosynthetic pigment levels in AVP1-OX plants. Whereas, RNAseq analysis uncovers the molecular mechanisms behind these responses. Glycomics analyses highlight AVP1 overexpression enhanced cell wall remodeling under both ground and spaceflight conditions, enhancing plant resilience and productivity under stressful environmental conditions.

Equity and Inclusion: Cotton is a global crop grown in regions with diverse environmental, social, and economic conditions. This proposal embraces diversity by incorporating advanced techniques from multiple disciplines, including plant biology, biochemistry, space biology, and agricultural research. We aim to publish these results soon in open-access journals, which will ensure that all community members, regardless of geographic or economic status, benefit equally from the advancements made. The inclusion of the spaceflight component highlights the importance of pushing boundaries in plant science, making this research inspiring and accessible to underrepresented groups in STEM fields.