Leaves play a central role in plant life by capturing light energy and producing essential nutrients. Their aging, marked by a progressive degradation of cells and tissues, represents a key stage in plant development. This process, often visible through leaf yellowing linked to the disappearance of chlorophyll, allows plants to recycle nutrients toward growing or storage organs. In annual plants like soybeans, rice, or corn, it leads to the death of the entire organism, while in deciduous trees, it prepares the shedding of leaves in autumn to better withstand winter.<\/p>\n
Leaf aging does not depend solely on age. It is also accelerated by external factors such as drought, nitrogen or carbon deficiencies, pathogen attacks, or extreme conditions of temperature, light, or salinity. These stresses activate complex hormonal signals, notably involving abscisic acid, a major hormone that regulates both stress response and aging. Under the influence of this hormone, specific genes activate, triggering chlorophyll degradation, anthocyanin production, and nutrient recycling.<\/p>\n
The molecular mechanisms at work are fine and interconnected. For example, abscisic acid acts in synergy with other hormones such as ethylene or jasmonic acid, which together modulate the sensitivity of leaves to aging. Proteins such as NAC transcription factors, or peptides like CLE14, play a key role in regulating the expression of genes associated with aging. CLE14, for instance, delays this process by stimulating the elimination of reactive oxygen species, toxic molecules that accumulate under stress.<\/p>\n
Water deficiencies, whether from drought or flooding, illustrate this complexity well. In the case of drought, abscisic acid causes the closure of stomata, leaf pores, to limit water loss, while triggering aging signals. Conversely, excess water in the soil suffocates the roots, reducing their ability to absorb oxygen and disrupting carbon metabolism. Deprived of resources, leaves then activate survival mechanisms that accelerate their own degradation.<\/p>\n
Nitrogen or sugar deficiencies have similar effects. A lack of nitrogen activates transcription factors such as ORE1, which accelerate aging to redistribute resources toward essential organs. Similarly, an excess or deficiency of sugars disrupts the plant’s energy balance, triggering chain reactions that lead to premature leaf degradation. Sugar transporters like OsSWEET1b in rice, or enzymes like hexokinase, play a direct role in this process.<\/p>\n
Abiotic stresses are not the only culprits. Pathogen or insect attacks also activate immune responses that, if too intense, can deplete the plant’s resources and accelerate aging. Salicylic acid, a key hormone in plant defense, is also a powerful inducer of aging. Its accumulation in infected leaves stimulates the production of reactive oxygen species and activates degradation genes, creating a vicious cycle that hastens senescence.<\/p>\n
In the face of these challenges, solutions are emerging thanks to advances in synthetic biology and artificial intelligence. Innovative genetic systems, such as the IPT<\/em> gene coupled with an aging-specific promoter, make it possible to delay senescence by stimulating the production of cytokinins, hormones that inhibit leaf degradation. This approach has already demonstrated its effectiveness in many species, from tobacco to rice, including tomatoes and cotton, improving tolerance to drought, cold, or excess water.<\/p>\n Artificial intelligence, for its part, is revolutionizing plant selection by analyzing massive amounts of genomic, transcriptomic, or metabolomic data. Machine learning or deep learning algorithms help identify key genes involved in aging or stress resistance and predict their impact on crop productivity. These tools pave the way for more precise agriculture, capable of designing plants optimized to withstand increasingly difficult environmental conditions.<\/p>\n These advances show that leaf aging, far from being a simple decline phenomenon, is a finely regulated process that can be exploited to improve crop resilience. By better understanding the signals and gene networks involved, scientists are developing strategies to delay or modulate this process, in order to maximize yield and harvest quality, even in hostile environments.<\/p>\n DOI:<\/strong> https:\/\/doi.org\/10.1186\/s43897-026-00236-9<\/a><\/p>\n Title:<\/strong> From signals to solutions: stress-induced leaf senescence and synthetic biology and AI approaches for crop resilience<\/p>\n Journal:<\/strong> Molecular Horticulture<\/p>\n Publisher:<\/strong> Springer Science and Business Media LLC<\/p>\n Authors:<\/strong> Shu-Ning Ren; Chen-Yu Zhu; Yu-Qiong Wang; Tian Bu; Zhonghai Li; Weilun Yin; Xinli Xia; Hou-Ling Wang<\/p>\n","protected":false},"excerpt":{"rendered":" Leaf aging under stress opens new avenues for more resilient crops Leaves play a central role in plant life by capturing light energy and producing essential nutrients. Their aging, marked by a progressive degradation of cells and tissues, represents a key stage in plant development. This process, often visible through leaf yellowing linked to the… Continue reading Leaf aging under stress opens new avenues for more resilient crops<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-41","post","type-post","status-publish","format-standard","hentry","category-non-classe","entry"],"_links":{"self":[{"href":"https:\/\/globalagriculturejournal.com\/en\/wp-json\/wp\/v2\/posts\/41","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/globalagriculturejournal.com\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/globalagriculturejournal.com\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/globalagriculturejournal.com\/en\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/globalagriculturejournal.com\/en\/wp-json\/wp\/v2\/comments?post=41"}],"version-history":[{"count":1,"href":"https:\/\/globalagriculturejournal.com\/en\/wp-json\/wp\/v2\/posts\/41\/revisions"}],"predecessor-version":[{"id":42,"href":"https:\/\/globalagriculturejournal.com\/en\/wp-json\/wp\/v2\/posts\/41\/revisions\/42"}],"wp:attachment":[{"href":"https:\/\/globalagriculturejournal.com\/en\/wp-json\/wp\/v2\/media?parent=41"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/globalagriculturejournal.com\/en\/wp-json\/wp\/v2\/categories?post=41"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/globalagriculturejournal.com\/en\/wp-json\/wp\/v2\/tags?post=41"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
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