Abstract

Phytochromes are involved in the expression of nutrient transporter genes and participate in signaling responses in plants under nutritional deficiency. This study investigated the reciprocal interaction between phytochrome B1 (phyB1) and N, P, and K deficiency responses, specifically focusing on shoot-root communication. For this purpose, we used grafting combinations of the control genotype (WT) with the tomato phyB1-deficient mutant (
phyB1
) under nutritional sufficiency and individual deficiencies of N, P, and K. In nutrient-sufficient conditions, shoot
phyB1
stimulated N and P uptake in the roots and increased stomatal conductance, transpiration, and dry weight accumulation , whereas root
phyB1
regulated the accumulation of chlorophyll in the shoot. With N deficiency, the WT/
phyB1
combination attenuated the damage caused by N deficiency by increasing the dry weight of the entire plant. Under P deficiency, the absence of root
phyB1
decreased N uptake and increased malondialdehyde (MDA) accumulation . However, the deficiency of phyB1 impaired the water-use efficiency of P-deficient plants. Under K deficiency, both shoot and root phyB1 modulated N and K uptake. Furthermore, shoot phyB1 influenced the oxidative status of leaf tissues, as indicated by variations in MDA content, and was associated with enhanced photosynthetic performance. These findings suggest that the phyB1-deficient mutant may have potential as a rootstock to attenuate damage caused by N deficiency in tomato. The results also demonstrate that phyB1 is involved in shoot-root communication for the control of nutritional, physiological, and growth responses in tomato, raising new roles of this photoreceptor and perspectives on the plant nutrition studies.

La Red Iberoamericana CYTED coordinada por Renato de Mello Prado (UNESP, Brasil) integra 15 grupos y 51 investigadores de Brasil, Chile, Colombia, Ecuador, México, Paraguay, Perú, Portugal y Uruguay para fomentar la colaboración en fertilidad de suelos, nutrición vegetal y manejo sustentable de cultivos, articulando universidades, institutos como Embrapa e INIA, universidades nacionales e internacionales y agencias de extensión. Dentro de este marco, el proyecto propuesto “El silicio es una estrategia para mitigar estreses para la sostenibilidad agroalimentaria de cultivos en Brasil, Perú, Paraguay, Colombia, Ecuador y Chile” (SiAgro, 2026-2029) posiciona el silicio como herramienta clave para enfrentar sequía, salinidad, enfermedades y deficiencias nutricionales en cultivos como maíz, arroz y caña, validando dosis y formas de aplicación (foliar, radicular, nano-Si), estudiando mecanismos fisiológicos, bioquímicos, moleculares (transportadores Lsi1/Lsi2, pared celular, antioxidantes) y promoviendo transferencia tecnológica para pequeños productores, con énfasis en resiliencia climática en suelos volcánicos, aluviales y tropicales.

Avocado is a very nutritious and tasty fruit, characteristics that have caused a high global demand for this fruit. Increasing evidence of health benefits of the avocado is both driving increased consumption and stimulating research. The results of this study are expected not only to provide more foundation into the agronomic, biochemical and molecular aspects associated to waterlogging of ‘Hass’ avocados grafted on different rootstocks but also provide potential biomarkers and genes involved in stress tolerance and select the best suited rootstocks for the current and the upcoming extreme climate change events, which may help to implement new Hass avocado production protocols that will reduce this predicted climate change problem in practice.

Anthropogenic climate change and its impacts on managed ecosystems pose a threat to global food security and the sustainability of farming systems. Rising temperatures, combined with more frequent and intense extreme weather events such as droughts and heatwaves, compromise agricultural productivity, the nutritional quality of food and its supply, raising costs and exposing the most vulnerable populations to food insecurity. Rising temperatures also impact the flow of greenhouse gases in ecosystems, both due to changes in the rate of carbon assimilation in biomass and changes in the rates of carbon dioxide, nitrous oxide and methane emissions from the soil. In recent decades, the technology of inoculating seeds with nitrogen-fixing (BFN) and plant growth-promoting (BPCV) bacteria, such as Bradyrhizobium spp. in legumes and Azospirillum brasilense and Pseudomonas fluorescens in grasses, has shown promising results, both by increasing productivity and by making plants more resilient to abiotic stresses. In this way, inoculation has the potential to mitigate the effects of the rise in temperature predicted for the coming decades. This mitigation potential will depend on both the magnitude of the temperature increase and the ability of these cultivated species to acclimatize in a heated atmosphere. Inoculation techniques also substantially reduce the use of nitrogen fertilizers, contributing to the mitigation of global warming by reducing nitrous oxide emissions from the soil. In this proposal, we will evaluate how agricultural crops and pastures of recognized economic importance, such as soybeans, sorghum, corn and Mombasa grass, will be impacted by a temperature increase of +2 °C and how the inoculation of BFN and BPCV can mitigate or amplify these effects. Physiological, nutritional, biochemical, plant growth and productivity parameters will be assessed, as well as the impacts on the soil microbiota and microclimate, and the emission of greenhouse gases in each crop. The experiments will be conducted under field conditions, using the outdoor plant heating system (T-FACE), in which automatically regulated infrared heaters keep the plants warm at +2 °C above the ambient temperature. This system is the only one in Latin America that allows temperature manipulation in field conditions, without physical limitations that alter the microclimate or restrictions on root growth, and is an excellent tool for studying the impact of future temperature increases in managed ecosystems. The results of this study will contribute to a more precise understanding of the future impacts of rising temperatures on the country’s main agricultural crops and the potential for mitigating these effects by inoculating plants with nitrogen-fixing and plant growth-promoting bacteria. These results could strengthen Brazilian agriculture, improving its resilience and increasing its competitiveness on the international stage. This previously unpublished data could improve the management of these species in the face of future climate change scenarios and provide important data for decision-makers.