Potential Biotechnological Applications of Autophagy for Agriculture

Abstract

Autophagy is a genetically regulated, eukaryotic cellular degradation system that sequestrates cytoplasmic materials in specialised vesicles, termed autophagosomes, for delivery and breakdown in the lysosome or vacuole. In plants, autophagy plays essential roles in development (e.g., senescence) and responses to abiotic (e.g., nutrient starvation, drought and oxidative stress) and biotic stresses (e.g., hypersensitive response). Initially, autophagy was considered a non-selective bulk degradation mechanism that provides energy and building blocks for homeostatic balance during stress. Recent studies, however, reveal that autophagy may be more subtle and selectively target ubiquitylated protein aggregates, protein complexes and even organelles for degradation to regulate vital cellular processes even during favourable conditions. The selective nature of autophagy lends itself to potential manipulation and exploitation as part of designer protein turnover machinery for the development of stress-tolerant and disease-resistant crops, crops with increased yield potential and agricultural efficiency and reduced post-harvest losses. Here, we discuss our current understanding of autophagy and speculate its potential manipulation for improved agricultural performance.

From Soil Amendments to Controlling Autophagy: Supporting Plant Metabolism under Conditions of Water Shortage and Salinity

“…These regulatory events are fine-tuned by a signaling network, including the upregulation of gene expression of several transcription factors [284,292,293]. Signal transduction includes post-translational protein modification, such as protein phosphorylation and de-phosphorylation [285,291,294].…”

“…To date, the available information makes autophagy a promising candidate for research projects that are aimed at improving crop stress resistance [291,294,295]. While molecular site directed mutation is possible at laboratory scale, the application of results in the field will possibly lack public acceptance in several countries.…”

“…While molecular site directed mutation is possible at laboratory scale, the application of results in the field will possibly lack public acceptance in several countries. Taking advantage of recent information, using plant growth promoting microorganisms might be a feasible approach [294].…”

The role of Atg16 in autophagy, anthocyanin biosynthesis, and programmed cell death in leaves of the lace plant (Aponogeton madagascariensis)

“…Autophagy is a process that sequesters and reutilizes intracellular contents mediated by double-membrane vesicles called autophagosomes which shuttle contents to the lysosome (animals) or vacuole (plants) for degradation and recycling [ 25 , 28 , 29 ]. The autophagy phenomenon in plants can play a dual role in promoting or inhibiting PCD making the ability to distinguish the exact function of autophagy in plant PCD difficult [ 28 , 30 – 32 ]. To study the core machinery behind autophagosome formation and fusion to lytic bodies, autophagy-related genes (ATGs) across eukaryotic models have been investigated and characterized.…”

MdHB7‐like positively modulates apple salt tolerance by promoting autophagic activity and Na+ efflux

“…Autophagy is a housekeeping pathway and is quickly induced by a variety of stressors, such as drought (Bao et al., 2020; Jia, Jia, et al., 2021; Sun, Wang, et al., 2018; Wang et al., 2015), salt stress (Huo, Guo, Jia, et al., 2020; Luo et al., 2017), heat (Thirumalaikumar et al., 2021), nutrient starvation (Huang et al., 2019; Huo, Guo, Zhang, et al., 2020; Zhang, Zhou, et al., 2022), oxidative stress (Wang et al., 2022; Zhang, Wang, et al., 2021), ion imbalances (Shinozaki & Yoshimoto, 2021), and pathogen attack (Hafren & Hofius, 2017; Signorelli et al., 2019; Zhang, Shao, et al., 2021). Several lines of evidence suggest that upregulating the expression of ATG genes improves autophagic activity, thereby enhancing stress tolerance by promoting the degradation of damaged macromolecules or organelles, increasing antioxidant enzyme activities, and promoting the accumulation of osmoregulatory substances (Tang & Bassham, 2022; Thanthrige et al., 2021; Wang, Cao, et al., 2019). NaCl treatments induces the transcription of several ATG genes, particularly ATG8 s and ATG18 s in Arabidopsis , rice, wheat, tobacco, pepper, and foxtail millet (Gong et al., 2005; Liu et al., 2009; Pei et al., 2014; Xia et al., 2011; Zhou et al., 2015).…”