Function of Small Peptides During Male-Female Crosstalk in Plants

Plant peptides secreted as signal molecular to trigger cell-to-cell signaling are indispensable for plant growth and development. Successful sexual reproduction in plants requires extensive communication between male and female gametophytes, their gametes, and with the surrounding sporophytic tissues. In the past decade, it has been well-documented that small peptides participate in many important reproductive processes such as self-incompatibility, pollen tube growth, pollen tube guidance, and gamete interaction. Here, we provide a comprehensive overview of the peptides regulating the processes of male-female crosstalk in plant, aiming at systematizing the knowledge on the sexual reproduction, and signaling of plant peptides in future.

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Multiple factors contribute to outcrossing in a tropical emergent Dipterocarpus tempehes, including a new pollen-tube guidance mechanism for self-incompatibility

American Journal of Botany ◽

10.3732/ajb.89.1.60 ◽

2002 ◽

Vol 89 (1) ◽

pp. 60-66 ◽

Cited By ~ 17

Author(s):

T. Kenta ◽

K. K. Shimizu ◽

M. Nakagawa ◽

K. Okada ◽

A. A. Hamid ◽

...

Keyword(s):

Pollen Tube ◽

Self Incompatibility ◽

Pollen Tube Guidance ◽

Multiple Factors

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753 PB 143 POLLEN-PISTIL INCOMPATIBILITY DIFFERENCES BETWEEN MANZANILLO AND FRANTOIO OLIVE (Olea europaea L.) CULTIVARS

HortScience ◽

10.21273/hortsci.29.5.541a ◽

1994 ◽

Vol 29 (5) ◽

pp. 541a-541 ◽

Cited By ~ 1

Author(s):

J. Cuevas ◽

L. Rallo ◽

H.F. Rapoport

Keyword(s):

Pollen Tube ◽

Reproductive Behavior ◽

Pollen Tube Growth ◽

Fruit Set ◽

Tube Growth ◽

Self Incompatibility ◽

Olive Cultivars ◽

Self Fertilization ◽

Incompatibility Reaction ◽

Reproductive Processes

We have compared reproductive processes and fruit set in Manzanillo and Frantoio olive cultivars which are reported in the literature respectively as incompatible and partially compatible. The same incompatibility reaction was observed in both cultivars. Pollen tube growth was almost completely inhibited beyond the stigma, but some degree of self-fertilization was accomplished. However, in both cultivars cross-pollination provided a earlier and higher level of fertilization. Differences in self-incompatibility behavior seemed related to the level and the amount of delay in self-fertilization. In the compatible variety, Frantoio, self-pollen tube growth was accomplished more rapidly and showed a higher level of self-fertilization than in the incompatible Manzanillo cultivar. Fruit set matched reproductive behavior.

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Cytokinin N-glucosides: Occurrence, Metabolism and Biological Activities in Plants

Biomolecules ◽

10.3390/biom11010024 ◽

2020 ◽

Vol 11 (1) ◽

pp. 24

Author(s):

Eva Pokorná ◽

Tomáš Hluska ◽

Petr Galuszka ◽

H. Tucker Hallmark ◽

Petre I. Dobrev ◽

...

Keyword(s):

Metabolic Pathways ◽

Growth And Development ◽

Biological Activities ◽

Physiological Effects ◽

Inhibitory Effects ◽

Plant Growth And Development ◽

The Past ◽

Complex Process ◽

Considerable Impact ◽

Physiological Impact

Cytokinins (CKs) are a class of phytohormones affecting many aspects of plant growth and development. In the complex process of CK homeostasis in plants, N-glucosylation represents one of the essential metabolic pathways. Its products, CK N7- and N9-glucosides, have been largely overlooked in the past as irreversible and inactive CK products lacking any relevant physiological impact. In this work, we report a widespread distribution of CK N-glucosides across the plant kingdom proceeding from evolutionary older to younger plants with different proportions between N7- and N9-glucosides in the total CK pool. We show dramatic changes in their profiles as well as in expression levels of the UGT76C1 and UGT76C2 genes during Arabidopsis ontogenesis. We also demonstrate specific physiological effects of CK N-glucosides in CK bioassays including their antisenescent activities, inhibitory effects on root development, and activation of the CK signaling pathway visualized by the CK-responsive YFP reporter line, TCSv2::3XVENUS. Last but not least, we present the considerable impact of CK N7- and N9-glucosides on the expression of CK-related genes in maize and their stimulatory effects on CK oxidase/dehydrogenase activity in oats. Our findings revise the apparent irreversibility and inactivity of CK N7- and N9-glucosides and indicate their involvement in CK evolution while suggesting their unique function(s) in plants.

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Testing of self-(in)compatibility in apricot cultivars from European breeding programmes

Horticultural Science ◽

10.17221/219/2012-hortsci ◽

2013 ◽

Vol 40 (No. 2) ◽

pp. 65-71 ◽

Cited By ~ 3

Author(s):

D. Milatović ◽

D. Nikolić ◽

B. Krška

Keyword(s):

Fluorescence Microscopy ◽

Pollen Tube ◽

Pollen Tube Growth ◽

Reliable Method ◽

Pollen Tubes ◽

Tube Growth ◽

Self Incompatibility ◽

Breeding Programmes

Self-(in)compatibility was tested in 40 new apricot cultivars from European breeding programmes. Pollen-tube growth in pistils from laboratory pollinations was analysed using the fluorescence microscopy. Cultivars were considered self-compatible if at least one pollen tube reached the ovary in the majority of pistils. Cultivars were considered self- incompatible if the growth of pollen tubes in the style stopped along with formation of characteristic swellings. Of the examined cultivars, 18 were self-compatible and 22 were self-incompatible. Fluorescence microscopy provides a relatively rapid and reliable method to determine self-incompatibility in apricot cultivars.      

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Flying Free: A Research Overview of Deep Learning in Drone Navigation Autonomy

Drones ◽

10.3390/drones5020052 ◽

2021 ◽

Vol 5 (2) ◽

pp. 52

Author(s):

Thomas Lee ◽

Susan Mckeever ◽

Jane Courtney

Keyword(s):

Deep Learning ◽

Research Work ◽

Learning Approaches ◽

Clear Definition ◽

Top Down ◽

Research Activity ◽

Comprehensive Overview ◽

The Past ◽

Computer Vision Applications ◽

Definition Of

With the rise of Deep Learning approaches in computer vision applications, significant strides have been made towards vehicular autonomy. Research activity in autonomous drone navigation has increased rapidly in the past five years, and drones are moving fast towards the ultimate goal of near-complete autonomy. However, while much work in the area focuses on specific tasks in drone navigation, the contribution to the overall goal of autonomy is often not assessed, and a comprehensive overview is needed. In this work, a taxonomy of drone navigation autonomy is established by mapping the definitions of vehicular autonomy levels, as defined by the Society of Automotive Engineers, to specific drone tasks in order to create a clear definition of autonomy when applied to drones. A top–down examination of research work in the area is conducted, focusing on drone navigation tasks, in order to understand the extent of research activity in each area. Autonomy levels are cross-checked against the drone navigation tasks addressed in each work to provide a framework for understanding the trajectory of current research. This work serves as a guide to research in drone autonomy with a particular focus on Deep Learning-based solutions, indicating key works and areas of opportunity for development of this area in the future.

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Hierarchical Reinforcement Learning

ACM Computing Surveys ◽

10.1145/3453160 ◽

2021 ◽

Vol 54 (5) ◽

pp. 1-35

Author(s):

Shubham Pateria ◽

Budhitama Subagdja ◽

Ah-hwee Tan ◽

Chai Quek

Keyword(s):

Reinforcement Learning ◽

Future Research ◽

Comprehensive Overview ◽

Open Problems ◽

Practical Applications ◽

Hierarchical Reinforcement Learning ◽

The Past ◽

Agent Learning ◽

Multi Agent ◽

Supplementary Material

Hierarchical Reinforcement Learning (HRL) enables autonomous decomposition of challenging long-horizon decision-making tasks into simpler subtasks. During the past years, the landscape of HRL research has grown profoundly, resulting in copious approaches. A comprehensive overview of this vast landscape is necessary to study HRL in an organized manner. We provide a survey of the diverse HRL approaches concerning the challenges of learning hierarchical policies, subtask discovery, transfer learning, and multi-agent learning using HRL. The survey is presented according to a novel taxonomy of the approaches. Based on the survey, a set of important open problems is proposed to motivate the future research in HRL. Furthermore, we outline a few suitable task domains for evaluating the HRL approaches and a few interesting examples of the practical applications of HRL in the Supplementary Material.

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Monotreme and marsupial reproduction

Reproduction Fertility and Development ◽

10.1071/rd9951003 ◽

1995 ◽

Vol 7 (5) ◽

pp. 1003 ◽

Cited By ~ 17

Author(s):

MB Renfree

Keyword(s):

Turn Of The Century ◽

Future Generations ◽

Future Research ◽

The Past ◽

Reproductive Processes

Marsupials were regarded as curiosities by their early European discoverers, animals to be wondered at. Monotremes were even more surprising; the platypus was such an amalgam of characters that it was thought to be a hoax. They were recognized very early as mammals that could make a major contribution to our understanding of reproductive processes, and work on marsupials at the turn of the century was much in evidence. It is, however, only in the past two decades, and especially in the past few years that marsupial research has regained this position. There is no doubt that future research will strengthen this contribution, but we are faced with serious conservation questions that must be solved if we are to maintain these wonderful animals as a resource for future generations.

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Glioblastoma Multiforme—A Look at the Past and a Glance at the Future

Pharmaceutics ◽

10.3390/pharmaceutics13071053 ◽

2021 ◽

Vol 13 (7) ◽

pp. 1053

Author(s):

Jasmine L. King ◽

Soumya Rahima Benhabbour

Keyword(s):

Glioblastoma Multiforme ◽

Immune Surveillance ◽

Standard Of Care ◽

Current Standard ◽

Comprehensive Overview ◽

Therapeutic Delivery ◽

The Past ◽

Adults And Children ◽

The Central Nervous System ◽

Delivery Strategies

Gliomas are the most common type of brain tumor that occur in adults and children. Glioblastoma multiforme (GBM) is the most common, aggressive form of brain cancer in adults and is universally fatal. The current standard-of-care options for GBM include surgical resection, radiotherapy, and concomitant and/or adjuvant chemotherapy. One of the major challenges that impedes success of chemotherapy is the presence of the blood–brain barrier (BBB). Because of the tightly regulated BBB, immune surveillance in the central nervous system (CNS) is poor, contributing to unregulated glioma cell growth. This review gives a comprehensive overview of the latest advances in treatment of GBM with emphasis on the significant advances in immunotherapy and novel therapeutic delivery strategies to enhance treatment for GBM.

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