Seasonal Pattern of Endo-β-Mannanase Activity During Germination of <i>Jeffersonia dubia</i>, Exhibiting Morphophysiological Dormancy

Morphophysiological dormancy (MPD) is considered one of the most primitive dormancy classes among seed plants. While extensive studies have examined the occurrence of endo-β-mannanase in seeds with physiological dormancy (PD) or non-dormancy, little is known about the activity of this enzyme in seed...

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Main Authors: Young Hyun Kwon, Seung Youn Lee, Yong Ha Rhie
Format: Article
Language:English
Published: MDPI AG 2025-01-01
Series:Plants
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Online Access:https://www.mdpi.com/2223-7747/14/2/251
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author Young Hyun Kwon
Seung Youn Lee
Yong Ha Rhie
author_facet Young Hyun Kwon
Seung Youn Lee
Yong Ha Rhie
author_sort Young Hyun Kwon
collection DOAJ
description Morphophysiological dormancy (MPD) is considered one of the most primitive dormancy classes among seed plants. While extensive studies have examined the occurrence of endo-β-mannanase in seeds with physiological dormancy (PD) or non-dormancy, little is known about the activity of this enzyme in seeds with MPD. This study aimed to investigate the temporal and spatial patterns of endo-β-mannanase activity during dormancy break and germination. The research focused on <i>Jeffersonia dubia</i>, a species with deep simple MPD, by monitoring its morphological and biochemical characteristics under natural field conditions. Seeds were buried in the field and exhumed monthly over a year. Key parameters measured included germination, embryo elongation, endosperm weakening, and endo-β-mannanase activity in the exhumed seeds. Scanning electron microscopy was employed to observe structural changes in the endosperm. For the first three months after burial in May, endo-β-mannanase activity was undetectable, and the underdeveloped embryo exhibited minimal elongation. Starting in September, the embryo began to grow, accompanied by increased endo-β-mannanase activity in the micropylar endosperm. Erosion of the endosperm cell wall was observed in the lateral regions surrounding the embryo, whereas the micropylar endosperm showed no obvious signs of collapse or damage. The increase in enzyme activity coincided with moderate temperatures and a corresponding increase in embryo length. During the winter months, embryo elongation ceased for 2–3 months, and enzyme activity declined. However, as germination resumed in early March, enzyme activity increased again. This was followed by micropylar endosperm rupture and the completion of germination. The seasonal pattern of endo-β-mannanase activity observed in seeds with deep simple MPD was distinct from that of seeds with PD, MD, or non-deep MPD, highlighting the unique mechanisms underlying dormancy break and germination in <i>J. dubia</i>.
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spelling doaj-art-c1e412d6096440c8a7a1372cd98107b42025-01-24T13:46:57ZengMDPI AGPlants2223-77472025-01-0114225110.3390/plants14020251Seasonal Pattern of Endo-β-Mannanase Activity During Germination of <i>Jeffersonia dubia</i>, Exhibiting Morphophysiological DormancyYoung Hyun Kwon0Seung Youn Lee1Yong Ha Rhie2Agriculture and Life Science Research Institute, Kangwon National University, Chuncheon 24341, Republic of KoreaDepartment of Smart Horticultural Science, Andong National University, Andong 36729, Republic of KoreaDepartment of Interdisciplinary Program in Smart Agriculture, Kangwon National University, Chuncheon 24341, Republic of KoreaMorphophysiological dormancy (MPD) is considered one of the most primitive dormancy classes among seed plants. While extensive studies have examined the occurrence of endo-β-mannanase in seeds with physiological dormancy (PD) or non-dormancy, little is known about the activity of this enzyme in seeds with MPD. This study aimed to investigate the temporal and spatial patterns of endo-β-mannanase activity during dormancy break and germination. The research focused on <i>Jeffersonia dubia</i>, a species with deep simple MPD, by monitoring its morphological and biochemical characteristics under natural field conditions. Seeds were buried in the field and exhumed monthly over a year. Key parameters measured included germination, embryo elongation, endosperm weakening, and endo-β-mannanase activity in the exhumed seeds. Scanning electron microscopy was employed to observe structural changes in the endosperm. For the first three months after burial in May, endo-β-mannanase activity was undetectable, and the underdeveloped embryo exhibited minimal elongation. Starting in September, the embryo began to grow, accompanied by increased endo-β-mannanase activity in the micropylar endosperm. Erosion of the endosperm cell wall was observed in the lateral regions surrounding the embryo, whereas the micropylar endosperm showed no obvious signs of collapse or damage. The increase in enzyme activity coincided with moderate temperatures and a corresponding increase in embryo length. During the winter months, embryo elongation ceased for 2–3 months, and enzyme activity declined. However, as germination resumed in early March, enzyme activity increased again. This was followed by micropylar endosperm rupture and the completion of germination. The seasonal pattern of endo-β-mannanase activity observed in seeds with deep simple MPD was distinct from that of seeds with PD, MD, or non-deep MPD, highlighting the unique mechanisms underlying dormancy break and germination in <i>J. dubia</i>.https://www.mdpi.com/2223-7747/14/2/251embryolateral endospermmicropylar endosperm<i>Plagiorhegma dubium</i>
spellingShingle Young Hyun Kwon
Seung Youn Lee
Yong Ha Rhie
Seasonal Pattern of Endo-β-Mannanase Activity During Germination of <i>Jeffersonia dubia</i>, Exhibiting Morphophysiological Dormancy
Plants
embryo
lateral endosperm
micropylar endosperm
<i>Plagiorhegma dubium</i>
title Seasonal Pattern of Endo-β-Mannanase Activity During Germination of <i>Jeffersonia dubia</i>, Exhibiting Morphophysiological Dormancy
title_full Seasonal Pattern of Endo-β-Mannanase Activity During Germination of <i>Jeffersonia dubia</i>, Exhibiting Morphophysiological Dormancy
title_fullStr Seasonal Pattern of Endo-β-Mannanase Activity During Germination of <i>Jeffersonia dubia</i>, Exhibiting Morphophysiological Dormancy
title_full_unstemmed Seasonal Pattern of Endo-β-Mannanase Activity During Germination of <i>Jeffersonia dubia</i>, Exhibiting Morphophysiological Dormancy
title_short Seasonal Pattern of Endo-β-Mannanase Activity During Germination of <i>Jeffersonia dubia</i>, Exhibiting Morphophysiological Dormancy
title_sort seasonal pattern of endo β mannanase activity during germination of i jeffersonia dubia i exhibiting morphophysiological dormancy
topic embryo
lateral endosperm
micropylar endosperm
<i>Plagiorhegma dubium</i>
url https://www.mdpi.com/2223-7747/14/2/251
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AT yongharhie seasonalpatternofendobmannanaseactivityduringgerminationofijeffersoniadubiaiexhibitingmorphophysiologicaldormancy