Light signaling as cellular integrator of multiple environmental cues in plants.

Plants being sessile need to rapidly adapt to the constantly changing environment through modifications in their internal clock, metabolism, and gene expression. They have evolved an intricate system to perceive and transfer the signals from the primary environmental factors namely light, temperature and water to regulate their growth development and survival. Over past few decades rigorous research using molecular genetics approaches, especially in model plant Arabidopsis, has resulted in substantial progress in discovering various photoreceptor systems and light signaling components. In parallel several molecular pathways operating in response to other environmental cues have also been elucidated. Interestingly, the studies have shown that expression profiles of genes involved in photomorphogenesis can undergo modulation in response to other cues from the environment. Recently, the photoreceptor, PHYB, has been shown to function as a thermosensor. Downstream components of light signaling pathway like COP1 and PIF have also emerged as integrating hubs for various kinds of signals. All these findings indicate that light signaling components may act as central integrator of various environmental cues to regulate plant growth and development processes. In this review, we present a perspective on cross talk of signaling mechanisms induced in response to myriad array of signals and their integration with the light signaling components. By putting light signals on the central stage, we propose the possibilities of enhancing plant resilience to the changing environment by fine-tuning the genetic manipulation of its signaling components in the future.

Molecular Characterization of NDL1-AGB1 Mediated Salt Stress Signaling: Further Exploration of the Role of NDL1 Interacting Partners.

Salt stress is considered to be the most severe abiotic stress. High soil salinity leads to osmotic and ionic toxicity, resulting in reduced plant growth and crop production. The role of G-proteins during salt stresses is well established. AGB1, a G-protein subunit, not only plays an important role during regulation of Na+ fluxes in roots, but is also involved in the translocation of Na+ from roots to shoots. N-Myc Downregulated like 1 (NDL1) is an interacting partner of G protein ßγ subunits and C-4 domain of RGS1 in Arabidopsis. Our recent in-planta expression analysis of NDL1 reported changes in patterns during salt stress. Based on these expression profiles, we have carried out functional characterization of the AGB1-NDL1 module during salinity stress. Using various available mutant and overexpression lines of NDL1 and AGB1, we found that NDL1 acts as a negative regulator during salt stress response at the seedling stage, an opposite response to that of AGB1. On the other hand, during the germination phase of the plant, this role is reversed, indicating developmental and tissue specific regulation. To elucidate the mechanism of the AGB1-NDL1 module, we investigated the possible role of the three NDL1 stress specific interactors, namely ANNAT1, SLT1, and IDH-V, using yeast as a model. The present study revealed that NDL1 acts as a modulator of salt stress response, wherein it can have both positive as well as negative functions during salinity stress. Our findings suggest that the NDL1 mediated stress response depends on its developmental stage-specific expression patterns as well as the differential presence and interaction of the stress-specific interactors.

Assessment of urban solid waste management systems for Industry 4.0 technology interventions and the circular economy.

The ongoing fourth industrial revolution, Industry 4.0 (I4.0), is transforming various industries across the globe. At the same time, resource scarcity with high consumption rates has led to the development of the circular economy. Both concepts advocate for sustainable growth and waste minimization. In developing countries, the integrated solid waste management framework is undergoing modification under I4.0 and the circular economy. Urban local bodies are often unable to measure the readiness of their waste management systems to transform under I4.0 and the circular economy. Here the novel concept of Waste 4.0 is developed. 'Waste 4.0' is a readiness assessment tool to promote the comprehensive transformation of municipal solid waste management under I4.0 and circular economy. This tool has eight determinants for assessing the municipal solid waste management of urban local bodies. To validate Waste 4.0 the urban local bodies of Indore and Sagar, India were used as case studies. The readiness index for I4.0 in the municipal solid waste management system in Indore and Sagar was 0.72 and 0.14, respectively. The readiness index for circular economy focus in Indore and Sagar was 0.65 and 0.13, respectively. The Indore urban local body was classified as an 'Experienced' player for I4.0 Intervention and a 'circular economy fast adopter' for circular economy focus under I4.0 readiness. The Sagar urban local body was classified as a 'Hesitator' player for I4.0 Intervention and achieved the 'Business as usual' tag for circular economy focus under I4.0 readiness. With the Waste 4.0 assessment results urban local bodies can better plan and thus transform their municipal solid waste management systems under I4.0 and the circular economy.