Plant perception of β-aminobutyric acid is mediated by an aspartyl-tRNA synthetase

Specific chemicals can prime the plant immune system for augmented defense. β-aminobutyric acid (BABA) is a priming agent that provides broad-spectrum disease protection. However, BABA also suppresses plant growth when applied in high doses, which has hampered its application as a crop defense activator. Here we describe a mutant of Arabidopsis thaliana that is impaired in BABA-induced disease immunity (ibi1) but is hypersensitive to BABA-induced growth repression. IBI1 encodes an aspartyl-tRNA synthetase. Enantiomer-specific binding of the R enantiomer of BABA to IBI1 primed the protein for noncanonical defense signaling in the cytoplasm after pathogen attack. This priming was associated with aspartic acid accumulation and tRNA-induced phosphorylation of translation initiation factor eIF2α. However, mutation of eIF2α-phosphorylating GCN2 kinase did not affect BABA-induced immunity but relieved BABA-induced growth repression. Hence, BABA-activated IBI1 controls plant immunity and growth via separate pathways. Our results open new opportunities to separate broad-spectrum disease resistance from the associated costs on plant growth

A multi-perspective discourse on the sustainability of water and sanitation service co-production in Global South cities

The article contributes to the debate on the sustainable provision of water supply and sanitation (WSS) services in Global South cities by developing a comprehensive understanding of the concept of sustainability when applied to the analysis of WSS co-production in these contexts. The study moves from the hypothesis that an integrated conceptualization of WSS co-production requires a re-discussion of evaluation approaches to questioning the sustainability of these unorthodox forms of service delivery. To this end, the study explores key dimensions of service sustainability through a complementary reading of the processes and the outcomes of WSS co-production practices on the basis of three theoretical perspectives: a governance-institutional, a socio/political-ecological and an incremental-urban. The objective is to frame a series of principles and criteria relevant for assessing the sustainability of WSS service co-production in Global South cities. The analysis is based on a systematic review of cross-cutting literatures on service co-production in the Global South, sustainable urban water management and urban studies. The review is integrated with empirical insights from four city-case studies of WSS co-production in the Global South, namely Hanoi (Vietnam), Addis Ababa (Ethiopia), Cochabamba (Bolivia) and Dar es Salaam (Tanzania).info:eu-repo/semantics/publishe