Biology subjects

Alagarasan, G.

Publications and source records attributed to Alagarasan, G..

4 recordsLinked to original sources

bioRxiv2024

Crops under continuous cultivation exhibit less plasticity than those under interrupted cultivation

Evolutionary studies indicate that species in stable environments often evolve with reduced plasticity, whereas those in variable environments tend to maintain higher plasticity to adapt to changing conditions. Our study explores whether this evolutionary principle extends to cultivated crops. In crop science, phenotypic plasticity is generally understood as a short-term response to environmental factors. Yet, the long-term evolutionary changes in both plastic and non-plastic traits under different cultivation regimes remain largely unexamined. Herein, we developed a novel mechanistic crop growth model, collectively termed the Trait-Environment Fitness Interaction (TEFI) Model, to study if and how trait plasticity varies among crops under different cultivation regimes. Our results, based on the TEFI Model, show higher trade-offs between fitness and plasticity. Specifically, we observed the evolution of higher plasticity in crops subjected to intermittent cultivation, which experienced more variable environments. However, this higher plasticity does not compensate for fitness losses due to the high rate of environmental unpredictability. Conversely, species under relatively stable conditions tend to evolve with reduced plasticity. Using real-world crop datasets, we validated the theoretical predictions of the TEFI Model, which suggest that the longer the interruption, the higher the plasticity. Our results highlight the evolutionary impact of cultivation patterns on trait plasticity and its importance in crop fitness. Ultimately, our findings illustrate how evolutionary principles of plasticity, as captured by the TEFI Model, can inform sustainable crop improvement strategies.

plant biology↗

bioRxiv2024

Distinct genetic architecture for trait mean and plasticity in chickpea

Crop plants often face rapid environmental changes, and their ability to adapt to novel conditions depends on whether specific traits can adjust to match these changes. This capacity for adjustment, known as phenotypic plasticity, is frequently regarded as a mere "response" rather than a distinct trait with its own genetic basis, particularly in agricultural science. As a result, plasticity is often oversimplified and viewed as an undesirable phenomenon when the goal is to achieve trait stability. In this study, we present a quantitative metric to measure phenotypic plasticity and provide evidence, through genome-wide association studies (GWAS) in chickpea, that plasticity is indeed a genetically based trait, comparable to any other agronomic trait. This foundational study paves the way for future GWAS efforts to harness phenotypic plasticity, offering new insights for crop improvement strategies.

plant biology↗

bioRxiv2024

High plasticity increases phenotype-environment mismatch leading to sub-optimal performance in underutilized crop species

As climate change threatens agricultural yields, crop diversification, including the reintroduction of underutilized species, has emerged as a proposed solution for resilience. But what determines the extent of environmental change that underutilized crop species can cope with upon their reintroduction? One critical factor is maladaptive plasticity, a theoretical concept suggesting that populations may respond negatively to rapid environmental shifts, at least in the short term. To test this empirically, we conducted a repeated-measures study using historically underutilized Amaranthus species as a model. Upon reintroduction, we observed higher plasticity in vegetative and reproductive traits than in life-history traits. This suggests that while these species adapt to immediate environmental changes through adjustments in growth and reproduction, limited plasticity in life-history traits may constrain long-term adaptation. Our study aimed to (1) identify the environmental factors driving these plastic responses, (2) determine whether these responses are maladaptive, and (3) assess if maladaptive plasticity also occurs within native environments. Using machine learning models, we found that temperature was a primary driver of plastic responses. Generalized Additive Model (GAM) reaction norm analysis further revealed these temperature-induced responses to be maladaptive, suggesting a mismatch between Amaranthus traits and the new environment. Applying transfer learning to predict responses in native settings, we found similar maladaptive responses to temperature, indicating that maladaptive plasticity may not be limited to non-native environments, thereby complicating climate adaptation efforts. This study underscore the need for detailed trait plasticity assessments before crop reintroduction for agricultural resilience.

plant biology↗

bioRxiv2018

Reaction of Hydrogen sulfide homeostasis genes under biotic and abiotic stress condition in rice -- computational approach

Gaseous molecules are widespread signaling compounds, regulating the cell development process in all major plant parts. For many decades, hydrogen sulfide molecule is considered mainly for its deleterious effects on plant system. The increasing recent experimental evidence and phenomenal concepts on H2S molecule further advance our understanding of H2S interaction with plant tissues. In addition, the H2S messenger molecule is found to have positive effects on plant growth, in limited condition, to maintain the balanced homeostasis. To meet the increasing demand, and to sustain the crop yield, various crop improvement programs have been followed. However, there is a concern that traditional plant improvement method and increasing climate change has a negative impact on crop production. A major approach to combating plant stress is to evaluate and explore the alternate source mechanism(s). Towards this aim, it will be valuable to characterize the genes involved in H2S homeostasis in the staple food crop rice pan-genome. In this research, we identified 15 H2S homeostasis genes in rice and used it for the ~3k rice pan-genome analysis to find out the genetic relatedness based on single nucleotide polymorphism data. Multidimensional scale plot of 15 H2S homeostasis genes among the rice cultivars, and RNA-seq experimental data analysis under various biotic and abiotic stress shows the functional genes involved in biotic and abiotic stress. This study provides new insights into plant stress management in crop breeding and suggests how H2S gene(s) can be utilized to improve the agronomic traits in rice and other food crops.

plant biology↗