A balancing act: how plants integrate nitrogen and water signals

Abstract

<jats:title>Abstract</jats:title> <jats:p>Nitrogen (N) and water (W) are crucial inputs for plant survival as well as costly resources for agriculture. Given their importance, the molecular mechanisms that plants rely on to signal changes in either N or W status have been under intense scrutiny. However, how plants sense and respond to the combination of N and W signals at the molecular level has received scant attention. The purpose of this review is to shed light on what is currently known about how plant responses to N are impacted by W status. We review classic studies which detail how N and W combinations have both synergistic and antagonistic effects on key plant traits, such as root architecture and stomatal aperture. Recent molecular studies of N and W interactions show that mutations in genes involved in N metabolism affect drought responses, and vice versa. Specifically, perturbing key N signaling genes may lead to changes in drought-responsive gene expression programs, which is supported by a meta-analysis we conduct on available transcriptomic data. Additionally, we cite studies that show how combinatorial transcriptional responses to N and W status might drive crop phenotypes. Through these insights, we suggest research strategies that could help to develop crops adapted to marginal soils depleted in both N and W, an important task in the face of climate change.</jats:p>

Effect of Two Different Sugarcane Cultivars on Rhizosphere Bacterial Communities of Sugarcane and Soybean Upon Intercropping

“…In addition, it also showed that intercropping with soybean could change the relative abundance of the sugarcane rhizosphere bacterial community and form a different rhizosphere bacterial community structure from that of single cropping sugarcane (Paungfoo-Lonhienne et al, 2017 ). Since the phenotypic structure of the root system had an impact on water absorption, the available N was mostly soluble in water, so many root structural features that promote water absorption (such as root length and diameter) could also generally improve the absorption rate of N (Araus et al, 2020 ).…”

“…These varieties have great advantages in yield and can replace the sugarcane varieties currently planted by farmers. Previous studies have found that ZZ1 and ZZ9 have differences in water-use efficiency, which also indicates differences in nitrogen use (Araus et al, 2020). Therefore, ZZ1 and ZZ9 may have different patterns when intercropped with soybean, and it is worth conducting an in-depth exploration of the intercropping benefits of these two varieties.…”

Early Changes in Nitrate Uptake and Assimilation Under Drought in Relation to Transpiration

“…Low NO 3 − availability can also lower the transpiration rate (TR; Wilkinson et al, 2007) and consequently affect water use by crops. Araus et al (2020) showed that changes in NO 3 − availability may lead to changes in the expression of droughtresponse genes; this response also involves the drought stress hormone abscisic acid (ABA). An interesting detail is that nitrogen supply to roots enhances stomatal opening, provided that plants are well watered (Wilkinson et al, 2007;Matimati et al, 2014).…”

Regulatory signatures of drought response in stress resilientSorghum bicolor

“…Alternatively, asparagine synthase ( asn; Sobic.001G406800) was up-regulated across tissues, which would suggest increased N assimilation relative to uptake. The processes regulating water and N uptake and use must be tightly interconnected, yet currently largely not understood (Araus et al, 2020)…”