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Biology subjects

Ben-Zeev, R.

Publications and source records attributed to Ben-Zeev, R..

3 recordsLinked to original sources

Crop yields under simulated nuclear winter: a growth chamber experiment

A global nuclear war could inject soot into the stratosphere, blocking sunlight and causing rapid cooling. Assessments of the resulting agricultural collapse rely on crop models never validated under such conditions. We grew wheat, canola, and potato in growth chambers simulating the light and temperature of an extreme nuclear winter at tropical and temperate sites. In the tropical chamber (18-20 {degrees}C, 200 mol m-2 s-1 PAR), all three crops produced viable yields. Wheat yielded 2.1-2.3 t/ha (n=3 well-watered, n=3 water-stressed pots), 60% of the global average, and single-pot observations of canola and potato suggested biological yields comparable to global averages. In the temperate chamber simulating nuclear winter irradiance (60-360 mol m-2 s-1), wheat stems collapsed under their own weight. Although hand-harvesting recovered 0.6-2.8 t/ha of grain, mechanical field harvest of a flat canopy would recover substantially less. This failure mode was not observed in a higher-light control chamber and is not captured by existing crop models, which may therefore overestimate temperate cereal production under nuclear winter. Canola produced comparable yields under both temperate light regimes without lodging. Empirical screening of additional staples is needed to identify which remain viable under nuclear winter.

plant biology↗

It's all in the timing: vegetative phase change alters selection under drought and contributes to local adaptation

The timing of developmental transitions is critical for adaptation, aligning stress-tolerant and sensitive stages with harsh and benign periods. At the same time, tradeoffs can promote diversity in development within populations. While geographic clines in developmental timing are often documented, there are few documented genetic tradeoffs in stress tolerance across developmental stages. Here, we study the juvenile-to-adult vegetative phase change (VPC), a conserved transition marked by changes in leaf morphology and physiology. In Arabidopsis, we found strong rank-changing genotype-by-environment interactions for fitness depending on the stage of drought exposure, indicating tradeoffs and stage-specific mechanisms of drought adaptation. Adult plants significantly increased water-use efficiency under drought, while juveniles did not, indicating lower juvenile plasticity. VPC timing varied with climate in Iberia, where genotypes from warm, dry climates transitioned earlier than those from cool, moist climates. However, SNPs associated with VPC timing and drought fitness showed little global geographic variation, suggesting tradeoffs maintain diversity across the species range. Genome-wide association mapping revealed candidate loci for VPC timing and stage-specific drought responses, several validated in T-DNA lines. Our results show that VPC timing contributes to drought adaptation and that genetic tradeoffs across developmental stages help maintain natural diversity.

plant biology↗

Neighbor sensing through rhizodeposits in sorghum affects plant physiology and productivity

Plant-plant interactions play a crucial role in shaping the growth environment for crops, impacting their productivity and stress response. The interaction between plants aboveground has been studied and incorporated into breeding programs that select for plants that reduce aboveground competition between plants. However, few studies have focused on belowground interactions, and these looked at combined interactions and root partitioning in the soil. This study focuses on the developmental and physiological responses of sorghum (Sorghum bicolor L.) genotypes to neighboring sorghum plants. In this study, we used two growing methods: i) a focal plant surrounded by neighboring plants in the same pot but without shading, and ii) a focal plant grown either alone or surrounded by neighbors, irrigated with nutrient solution passed through pots (leachates) with or without plants. Our results showed that the presence of neighbors in the same pot led to reduced size-dry weight height, and leaf area of the focal plant. In addition, the presence of neighbors reduced stomatal conductance and PSII quantum yield. While the response direction was similar across tested genotypes, the magnitude varied. The results were repeated when neighboring plants were not grown in the same pot, but the nutrient solution passed through the root system of plants of the neighboring genotype. Furthermore, we saw a reduction in assimilation rate and stomatal conductance when plants were exposed to either the physical presence of neighbors or leachate. We did not find differences in root architecture in either treatment. These results show plants change their growth in response to neighbors and that the signal is carried through the liquid phase of the soil. Our findings provide insights into sorghum plants responses to below-ground signaling from neighboring plants and lay the foundation for future studies enabling increased crop performance under high-density planting conditions.

plant biology↗