Biology subjects

Thakur, D.

Publications and source records attributed to Thakur, D..

3 recordsLinked to original sources

bioRxiv2023

Heterologous Expression and Characterization of ToxA1 haplotype from India and its interaction with for Spot Blotch Susceptibility in spring wheat

BackgroundToxA, a necrotrophic effector protein, is present in the genome of fungal species like Parastagnospora nodorum, Pyrenophora tritici-repentis and Bipolaris sorokiniana. Tsn1 is the sensitivity gene in the host whose presence indicates more susceptibility to ToxA carrying pathogen, and ToxA-Tsn1 interaction follows an inverse gene-for-gene relationship. Methods and ResultsThe present study involved cloning and expressing the ToxA1 haplotype from B. sorokiniana. It was found that the amplicon exhibited an expected product size of 471 bp. Sequence analysis of the ToxA1 nucleotide sequence revealed the highest identity, 99.79%, with P. tritici-repentis. The protein expression analysis showed peak expression at 16.5kDa. Phylogenetic analysis of the ToxA1 sequence from all the Bipolaris isolates formed an independent clade along with P. tritici-repentis and diverged from P. nodorum. ToxA-Tsn1 interaction was studied in 18 wheat genotypes (11 Tsn1 and 7 tsn1) at both seedling and adult stages, validating the inverse gene-for-gene relationship, as the toxin activity was highest in the K68 genotype (Tsn1) and lowest in WAMI280 (tsn1). ConclusionThe study indicates that the haplotype ToxA1 is prevailing in the Indian population of B. sorokiniana. It would be desirable for wheat breeders to select genotypes with tsn1 locus for making wheat resistant to spot blotch.

plant biology↗

bioRxiv2022

Differential effect of climate on structural and biochemical plant traits

Exploring patterns and causes of intraspecific trait variation is crucial for a better understanding of the effects of climate change on plant populations and ecosystems. However, our current understanding of the intraspecific trait variation is mainly based on structural (morphological) traits, and we have limited knowledge on patterns and causes of variation in biochemical traits (e.g., leaf pigments), which are also crucial for plant adaptation. As a result, we also do not know how similar the climatic effects on structural versus biochemical traits are. Using plant traits from 110 genotypes representing 11 Festuca rubra populations grown in 4 different climates, we studied trait covariation among structural traits (linked to fitness, resource use, gas exchange, and reproduction) and biochemical traits (linked to photosynthesis, photoprotection, and oxidative stress). We also disentangled the relative role of the climate of origin and the climate of cultivation in the structural versus biochemical traits and tested for adaptive plasticity in the traits. We found that 1) biochemical traits did not covary with structural traits and represent independent photoharvesting - photoprotection strategy dimension of functional variation; 2) interactive effects of climate of origin and cultivation were more pronounced for biochemical than structural traits. 3) Trait plasticity was affected by the climate of origin (precipitation and temperature as well as their interaction); 4) F. rubra showed both adaptive and mal-adaptive plasticity, and adaptiveness depended upon trait type, cultivation climate, and climate of origin. Overall, our results suggest that structural and biochemical plant traits respond differentially to climate and thus the response of one group of traits cannot be predicted from the other. Responses are also strongly determined by interactions between the climate of origin and cultivation. Thus, more studies on variation in biochemical traits, their correspondence to other traits, and their variation with climate are needed.

ecology↗

bioRxiv2021

Rhizome trait scaling relationships are modulated by climate and are linked to plant fitness

Background and AimRhizomes are important organs allowing many clonal plants to persist and reproduce under stressful climates with longer rhizomes indicating enhanced ability of the plants to spread vegetatively. We do not however, know either how rhizome construction costs change with increasing length or vary with environmental conditions. MethodsWe analysed the rhizome length vs mass scaling relationship, the plasticity in the scaling relationships, their genetic basis, and how scaling relationships are linked to plant fitness. We used data from 275 genotypes of a clonal grass Festuca rubra originating from 11 localities and cultivated under four contrasting climates. Data were analysed using standard major axis regression, mixed-effect regression models and a structural equation model. Key ResultsRhizome construction costs increased (i.e., lower specific rhizome length) with increasing length. The trait scaling relationships were modulated by cultivation climate and its effects also interacted with the climate of origin of the experimental plants. With increasing length, increasing moisture led to a greater increase in rhizome construction costs. Plants with lower rhizome construction costs showed significantly higher fitness. ConclusionsThis study suggests that rhizome scaling relationships are plastic, but also show genetic differentiation and are linked to plant fitness. Therefore, to persist under variable environments modulation in scaling relationships could be an important plants strategy.

ecology↗