Leaf shedding as a bacterial defense in Arabidopsis cauline leaves

Patharkar, O. Rahul; Gassmann, Walter; Walker, John C.

doi:10.1101/189720

Cited by 5 publications

(1 citation statement)

References 55 publications

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“…Currently, drought is known to trigger cauline leaf abscission; however, biotic stimuli may also initiate it (Patharkar and Walker, 2016). Thus, pathogen-triggered leaf abscission appears to be an effector mechanism eliminating disease leaves, which reduces the possibility of infection spreading to healthy tissue (Patharkar et al, 2017). For example, necrotrophic pathogens -such as Cylindrocladium sp-kill host plant cells using toxic metabolites and then feed on the remains.…”

Section: Discussionmentioning

confidence: 99%

Quantification of shedding of leaves in yerba mate and determination of associated hormonal levels

Molina¹,

Andrade²,

Bruera³

et al. 2022

SEAS

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In recent years, leaf shedding in the yerba mate crop has been a phenomenon of important economic incidence, the cause of which is still unknown but has been attributed to various factors. The objective of the present study was to establish a methodology to quantify leaves shedding in yerba mate and to determine whether the high leaf shedding is due to a biotic or abiotic effect. In both plantations, high shedding of leaves was significant only when the lowest values of heliophany and the highest values of relative humidity were recorded. Coincidentally, a high percentage of green leaf detachment was recorded with the characteristic symptomatology of the fungus Cylindrocladium sp. An accumulation of ABA, JA and SA hormones was detected in yerba mate plants with high shedding of leaves, which was associated with the attack of the necrotrophic fungus Cylindrocladium sp. With predisposing climatic conditions for the manifestation of Cylindrocladium, an early harvest would reduce the loss of green leaves. The differences found among plants Cylindrocladium attack could be due to a genetic condition. The JA pathway may be the most important line of defense activated by Cylindrocladium infection. A high accumulation of JA and ABA has been detected in plants with high leaf shedding that could suppress the SA signaling pathway responsible for SAR establishment.

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Section: Discussionmentioning

confidence: 99%

Quantification of shedding of leaves in yerba mate and determination of associated hormonal levels

Molina¹,

Andrade²,

Bruera³

et al. 2022

SEAS

View full text Add to dashboard Cite

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Chemical Defoliant Promotes Leaf Abscission by Altering ROS Metabolism and Photosynthetic Efficiency in Gossypium hirsutum

Jin

Wang

et al. 2020

IJMS

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Chemical defoliation is an important part of cotton mechanical harvesting, which can effectively reduce the impurity content. Thidiazuron (TDZ) is the most used chemical defoliant on cotton. To better clarify the mechanism of TDZ promoting cotton leaf abscission, a greenhouse experiment was conducted on two cotton cultivars (CRI 12 and CRI 49) by using 100 mg L −1 TDZ at the eight-true-leaf stage. Results showed that TDZ significantly promoted the formation of leaf abscission zone and leaf abscission. Although the antioxidant enzyme activities were improved, the reactive oxygen species and malondialdehyde (MDA) contents of TDZ increased significantly compared with CK (water). The photosynthesis system was destroyed as net photosynthesis (Pn), transpiration rate (Tr), and stomatal conductance (Gs) decreased dramatically by TDZ. Furthermore, comparative RNA-seq analysis of the leaves showed that all of the photosynthetic related genes were downregulated and the oxidation-reduction process participated in leaf shedding caused by TDZ. Consequently, a hypothesis involving possible cross-talk between ROS metabolism and photosynthesis jointly regulating cotton leaf abscission is proposed. Our findings not only provide important insights into leaf shedding-associated changes induced by TDZ in cotton, but also highlight the possibility that the ROS and photosynthesis may play a critical role in the organ shedding process in other crops.Previous studies have found that ethylene accelerates organ abscission, while auxin inhibits this process [5][6][7][8][9]. Meanwhile, researchers have paid attention to the fact that multiple cell wall-degrading enzymes are activated to dissolve the cell wall and middle lamella of abscission zone, including cellulases, pecticlyases, polygalactosidases [10][11][12]. Some research has found that hydrogen peroxide (H 2 O 2 ) acts downstream from ethylene and plays a role in the cell-wall degradation process in abscission signaling [13,14].Reactive oxygen species (ROS), including H 2 O 2 , superoxide, singlet oxygen, and the hydroxyl radical, are produced in response to environmental stress [13]. Environmental stresses (such as drought, cold stress, salt stress, and pathogen attack) are often accompanied by leaf abscission [15][16][17], but the relationship between stress and abscission is rarely studied. Excessive ROS can damage cellular components, including lipids, protein, and nucleic acids [18]. ROS produced at the abscission zone site play an important role in regulating leaf abscission under drought stress in cassava (Manihot esculenta Crantz) [19]. Recent studies have found that ROS do not work in the fruit abscission zone of olives (Olea europaea L.), but only alter oxidative stress in the abscission zone of leaves and then mediate abscission induced by ethephon [20]. Previous studies have shown that insufficient carbohydrate accumulation and distribution can lead to flower and fruit abscission. For example, carbohydrate stress can induce longan (Dimocarpus longan Lour.) fruit abscissi...

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Advances in Rice Seed Shattering

Wang

2023

IJMS

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Seed shattering is an important trait that wild rice uses to adapt to the natural environment and maintain population reproduction, and weedy rice also uses it to compete with the rice crop. The loss of shattering is a key event in rice domestication. The degree of shattering is not only one of the main reasons for rice yield reduction but also affects its adaptability to modern mechanical harvesting methods. Therefore, it is important to cultivate rice varieties with a moderate shattering degree. In this paper, the research progress on rice seed shattering in recent years is reviewed, including the physiological basis, morphological and anatomical characteristics of rice seed shattering, inheritance and QTL/gene mapping of rice seed shattering, the molecular mechanism regulating rice seed shattering, the application of seed-shattering genes, and the relationship between seed-shattering genes and domestication.

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Leaf shedding as a bacterial defense in Arabidopsis cauline leaves

Cited by 5 publications

References 55 publications

Quantification of shedding of leaves in yerba mate and determination of associated hormonal levels

Quantification of shedding of leaves in yerba mate and determination of associated hormonal levels

Chemical Defoliant Promotes Leaf Abscission by Altering ROS Metabolism and Photosynthetic Efficiency in Gossypium hirsutum

Advances in Rice Seed Shattering

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