Low Light/Darkness as Stressors of Multifactor-Induced Senescence in Rice Plants

Leaf senescence, as an integral part of the final development stage for plants, primarily remobilizes nutrients from the sources to the sinks in response to different stressors. The premature senescence of leaves is a critical challenge that causes significant economic losses in terms of crop yields. Although low light causes losses of up to 50% and affects rice yield and quality, its regulatory mechanisms remain poorly elucidated. Darkness-mediated premature leaf senescence is a well-studied stressor. It initiates the expression of senescence-associated genes (SAGs), which have been implicated in chlorophyll breakdown and degradation. The molecular and biochemical regulatory mechanisms of premature leaf senescence show significant levels of redundant biomass in complex pathways. Thus, clarifying the regulatory mechanisms of low-light/dark-induced senescence may be conducive to developing strategies for rice crop improvement. This review describes the recent molecular regulatory mechanisms associated with low-light response and dark-induced senescence (DIS), and their effects on plastid signaling and photosynthesis-mediated processes, chloroplast and protein degradation, as well as hormonal and transcriptional regulation in rice.

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Fertiliser evenness - losses and costs: A study on the economic benefits of uniform applications of fertiliser

Proceedings of the New Zealand Grassland Association ◽

10.33584/jnzg.1999.61.2337 ◽

1999 ◽

pp. 215-220 ◽

Cited By ~ 2

Author(s):

R. Horrell ◽

A.K. Metherell ◽

S. Ford ◽

C. Doscher

Keyword(s):

Crop Yields ◽

Cumulative Effect ◽

Economic Loss ◽

Economic Benefits ◽

Significant Loss ◽

Economic Losses ◽

Financial Return ◽

Spread Pattern ◽

Fertiliser Application ◽

Seed Crops

Over two million tonnes of fertiliser are applied to New Zealand pastures and crops annually and there is an increasing desire by farmers to ensure that the best possible economic return is gained from this investment. Spreading distribution measurements undertaken by Lincoln Ventures Ltd (LVL) have identified large variations in the evenness of fertiliser application by spreading machines which could lead to a failure to achieve optimum potential in some crop yields and to significant associated economic losses. To quantify these losses, a study was undertaken to calculate the effect of uneven fertiliser application on crop yield. From LVL's spreader database, spread patterns from many machines were categorised by spread pattern type and by coefficient of variation (CV). These patterns were then used to calculate yield losses when they were combined with the response data from five representative cropping and pastoral situations. Nitrogen fertiliser on ryegrass seed crops shows significant production losses at a spread pattern CV between 30% and 40%. For P and S on pasture, the cumulative effect of uneven spreading accrues, until there is significant economic loss occurring by year 3 for both the Waikato dairy and Southland sheep and beef systems at CV values between 30% and 40%. For nitrogen on pasture, significant loss in a dairy system occurs at a CV of approximately 40% whereas for a sheep and beef system it is at a CV of 50%, where the financial return from nitrogen application has been calculated at the average gross revenue of the farming system. The conclusion of this study is that the current Spreadmark standards are a satisfactory basis for defining the evenness requirements of fertiliser applications in most circumstances. On the basis of Spreadmark testing to date, more than 50% of the national commercial spreading fleet fails to meet the standard for nitrogenous fertilisers and 40% fails to meet the standard for phosphatic fertilisers.Keywords: aerial spreading, crop response, economic loss, fertiliser, ground spreading, striping, uneven application, uneven spreading, yield loss

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Further insights into how low-light signaling delays leaf senescence in soybean under high- temperature

Environmental and Experimental Botany ◽

10.1016/j.envexpbot.2021.104516 ◽

2021 ◽

pp. 104516

Author(s):

George Bawa ◽

Guopeng Chen ◽

Jianyi Shi ◽

Chen Ping ◽

Lingyang Feng ◽

...

Keyword(s):

High Temperature ◽

Leaf Senescence ◽

Light Signaling ◽

Low Light

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PR-1-Like Protein as a Potential Target for the Identification of Fusarium oxysporum: An In Silico Approach

BioTech ◽

10.3390/biotech10020008 ◽

2021 ◽

Vol 10 (2) ◽

pp. 8

Author(s):

Olalekan Olanrewaju Bakare ◽

Arun Gokul ◽

Marshall Keyster

Keyword(s):

Antimicrobial Peptides ◽

Fusarium Oxysporum ◽

In Silico ◽

Crop Yields ◽

Research Work ◽

Receptor Protein ◽

Economic Losses ◽

Protein Receptor ◽

Novel Biomarkers ◽

Docking Interaction

Fusarium oxysporum remains one of the leading causes of economic losses and poor crop yields; its detection is strained due to its presentation in various morphological and physiological forms. This research work sought to identify novel biomarkers for the detection of Fusarium oxysporum using in silico approaches. Experimentally validated anti-Fusarium oxysporum antimicrobial peptides (AMPs) were used to construct a profile against Fusarium oxysporum. The performance and physicochemical parameters of these peptides were predicted. The gene for the Fusarium oxysporum receptor protein PR-1-like Protein, Fpr1, was identified and translated. The resulting protein model from the translation was then validated. The anti-Fusarium oxysporum AMPs and Fusarium oxysporum receptor protein 3-D structures were characterized, and their docking interaction analyses were carried out. The HMMER in silico tool identified novel anti-Fusarium oxysporum antimicrobial peptides with good performance in terms of accuracy, sensitivity, and specificity. These AMPs also displayed good physicochemical properties and bound with greater affinity to Fusarium oxysporum protein receptor PR-1-like Protein. The tendency of these AMPs to precisely detect Fusarium oxysporum PR-1-like Protein, Fpr1, would justify their use for the identification of the fungus. This study would enhance and facilitate the identification of Fusarium oxysporum to reduce problems associated with poor crop yield, economic losses, and decreased nutritional values of plants to keep up with the growing population.

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Early Detection of Encroaching Woody Juniperus virginiana and Its Classification in Multi-Species Forest Using UAS Imagery and Semantic Segmentation Algorithms

Remote Sensing ◽

10.3390/rs13101975 ◽

2021 ◽

Vol 13 (10) ◽

pp. 1975

Author(s):

Lin Wang ◽

Yuzhen Zhou ◽

Qiao Hu ◽

Zhenghong Tang ◽

Yufeng Ge ◽

...

Keyword(s):

Early Detection ◽

Early Development ◽

Spatial Resolution ◽

Early Stage ◽

Semantic Segmentation ◽

Development Stage ◽

Unmanned Aircraft ◽

Economic Losses ◽

Juniperus Virginiana ◽

Segmentation Algorithms

Woody plant encroachment into grasslands ecosystems causes significantly ecological destruction and economic losses. Effective and efficient management largely benefits from accurate and timely detection of encroaching species at an early development stage. Recent advances in unmanned aircraft systems (UAS) enabled easier access to ultra-high spatial resolution images at a centimeter level, together with the latest machine learning based image segmentation algorithms, making it possible to detect small-sized individuals of target species at early development stage and identify them when mixed with other species. However, few studies have investigated the optimal practical spatial resolution of early encroaching species detection. Hence, we investigated the performance of four popular semantic segmentation algorithms (decision tree, DT; random forest, RF; AlexNet; and ResNet) on a multi-species forest classification case with UAS-collected RGB images in original and down-sampled coarser spatial resolutions. The objective of this study was to explore the optimal segmentation algorithm and spatial resolution for eastern redcedar (Juniperus virginiana, ERC) early detection and its classification within a multi-species forest context. To be specific, firstly, we implemented and compared the performance of the four semantic segmentation algorithms with images in the original spatial resolution (0.694 cm). The highest overall accuracy was 0.918 achieved by ResNet with a mean interaction over union at 85.0%. Secondly, we evaluated the performance of ResNet algorithm with images in down-sampled spatial resolutions (1 cm to 5 cm with 0.5 cm interval). When applied on the down-sampled images, ERC segmentation performance decreased with decreasing spatial resolution, especially for those images coarser than 3 cm spatial resolution. The UAS together with the state-of-the-art semantic segmentation algorithms provides a promising tool for early-stage detection and localization of ERC and the development of effective management strategies for mixed-species forest management.

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Changes in levels of foliar carbohydrates and myo-inositol before premature leaf senescence of Populus nigra induced by a mixture of O3 and SO2

Canadian Journal of Botany ◽

10.1139/b96-120 ◽

1996 ◽

Vol 74 (6) ◽

pp. 965-970 ◽

Cited By ~ 11

Author(s):

R. C. Fialho ◽

J. Bücker

Keyword(s):

Air Pollution ◽

Leaf Senescence ◽

Populus Nigra ◽

Continuous Exposure ◽

Nonstructural Carbohydrates ◽

Progressive Decline ◽

Total Nonstructural Carbohydrates ◽

Leaf Yellowing ◽

Premature Leaf Senescence ◽

Early Indication

Specimens of Populus nigra L. cv. Loenen exhibit premature leaf senescence when exposed for a few weeks to realistic air pollution. In this study, the changes in levels of foliar carbohydrates and myo-inositol (MI) due to 30 ± 1 nL/L O3 + 12 ± 1 nL/L SO2 from the onset of exposure to the occurrence of premature abscission is presented. Petioles and laminae of the 12 oldest leaves were separately analysed on days 0, 4, 8, 12, 16, 20, 22, and 32 of continuous exposure, which was performed in open-top chambers (OTC). On days 8 to 12, clearly prior to yellowing (starting on day 22), total nonstructural carbohydrates (TNC; starch + raffinose + sucrose + glucose + fructose + MI) in the fumigated laminae exceeded that in controls by about 30%. This increase was due to higher amounts of different soluble forms, while starch remained unaltered. From day 20 onwards, the level of TNC in the fumigated laminae progressively fell below that in controls. This decrease was due to a progressive decline in starch, which had started on day 16 and was dominating, although glucose and raffinose increased significantly. In the petioles, starch, sucrose, and glucose decreased because of fumigation with the occurrence of leaf yellowing, while raffinose increased. In contrast, MI in the petioles progressively accumulated directly on exposure until leaf yellowing occurred. The results are discussed in terms of the "general adaption syndrome" of H. Selye (1936. Nature (London), 138: 32). The marked MI response in petioles is concluded to be an early indication of phytorelevant O3 + SO2 pollution. Keywords: air pollution, carbohydrates, myo-inositol, pigments, Populus nigra L., senescence, stress.

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Extension Plant Pathology: Strengthening Resources to Continue Serving the Public Interest

Phytopathology ◽

10.1094/phyto-09-11-0251 ◽

2012 ◽

Vol 102 (7) ◽

pp. 652-655 ◽

Cited By ~ 2

Author(s):

K. L. Everts ◽

L. Osborne ◽

A. J. Gevens ◽

S. J. Vasquez ◽

B. K. Gugino ◽

...

Keyword(s):

Plant Pathology ◽

Plant Disease ◽

Crop Yields ◽

Economic Value ◽

The United States ◽

Emerging Diseases ◽

Plant Diseases ◽

Economic Losses ◽

Global Competitiveness ◽

Horticultural Crops

Extension plant pathologists deliver science-based information that protects the economic value of agricultural and horticultural crops in the United States by educating growers and the general public about plant diseases. Extension plant pathologists diagnose plant diseases and disorders, provide advice, and conduct applied research on local and regional plant disease problems. During the last century, extension plant pathology programs have adjusted to demographic shifts in the U.S. population and to changes in program funding. Extension programs are now more collaborative and more specialized in response to a highly educated clientele. Changes in federal and state budgets and policies have also reduced funding and shifted the source of funding of extension plant pathologists from formula funds towards specialized competitive grants. These competitive grants often favor national over local and regional plant disease issues and typically require a long lead time to secure funding. These changes coupled with a reduction in personnel pose a threat to extension plant pathology programs. Increasing demand for high-quality, unbiased information and the continued reduction in local, state, and federal funds is unsustainable and, if not abated, will lead to a delay in response to emerging diseases, reduce crop yields, increase economic losses, and place U.S. agriculture at a global competitive disadvantage. In this letter, we outline four recommendations to strengthen the role and resources of extension plant pathologists as they guide our nation's food, feed, fuel, fiber, and ornamental producers into an era of increasing technological complexity and global competitiveness.

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Analysis of the Influence of the Application of Effective Microorganisms on the Dynamics of Spring Wheat Emergence

Rocznik Ochrona Środowiska ◽

10.54740/ros.2021.048 ◽

2021 ◽

Vol 23 ◽

pp. 684-693

Author(s):

Anna Piotrowska

Keyword(s):

Seed Germination ◽

Spring Wheat ◽

Natural Environment ◽

Crop Yields ◽

Regulatory Mechanisms ◽

Wheat Seed ◽

Effective Microorganisms ◽

Seed Dressing ◽

Microbial Preparation

Deterioration of the natural environment as a result of violation of its natural structures and self-regulatory mechanisms causes an urgent need to replace chemicals with effective and multidirectional biopreparations. Reduction of the amount of chemicals used in agriculture becomes possible through the use of Effective Microorganisms. This will reduce the burden on the environment. Agriculture that uses EM technology can count on help with germination rates; emergence uniformity; and crop yields, for example. EM formulations contain a mixture of different coexisting microorganisms. The following paper presents the results of own research on the use of Effective Microorganisms in seed dressing of spring wheat. It was shown that the microbial preparation EM Naturally Active affects the increase of wheat seed germination dynamics.

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