140
by the type of soil, pH value, as well as the content of organic matter in the soil
(Stankovic et al. 2018). Representing parts of some enzyme complexes and proteins, essential heavy metals are necessary for normal plant growth and development. However, the mentioned accumulation of heavy metals can be a consequence
of binding to SH groups of proteins and result in inhibition of enzyme activity, disruption of their structure, deficiency of essential metals, and stimulation of production of free radical species, causing oxidative stress (De Miguel et al. 1999).
Accumulation of heavy metals causes inhibition of growth of aboveground and
underground parts, reduction of seed germination, reduction of photosynthetic pigments, formation of chlorosis and leaf necrosis, and loss of turgor, which is related
to accelerated aging and death of the plant itself. Toxic metals lead to changes in the
structure of plant tissue and biochemical and molecular processes (Jӓrup 2003).
5.2.4 The Effects of Heavy Metals on Bryophytes
Though growth and development are commonly used parameters for the assessment of the heavy metal toxicity in plants, negative effects of heavy metal pollution could be detected before the alteration of these two parameters become
obvious (Wolterbeek 2002). These effects include ultrastructural changes as well
as the changes in the plant physiological processes and characteristics (Stankovic
et al. 2018). Ultrastructural changes seen in bryophytes under heavy metal stress
are evident (Stankovic et al. 2018). Along with the ultrastructural changes, heavy
metals may also disrupt various metabolic processes. These negative effects could
be explained by the high affinity of heavy metals for sulfhydryl groups in various
proteins (Boquete et al. 2014; Stankovic et al. 2018). The chlorophyll content can
be also used as a tracking signal for assessment of the physiological state and
biochemical functionality of plant organism (Nagajyoti et al. 2010). However,
there have not been many studies investigating the relationship between the presence of different heavy metals in bryophytes and the chlorophyll concentration
(Stankovic et al. 2018).
5.2.5 Intracellular and Surface-Bound Fractions of Elements
Just like other terrestrial plants, mosses have adapted to life on land: the waxy cuticle is a protection against dehydration, gas exchange takes place through the coup,
and their zygote remains protected within the female sexual organ (archegonia)
developing into a multicellular embryo. Mosses with terrestrial plants share some
other significant features: they are parenchymal structures, and their life cycle
consists of heteromorphic and heterophase generation change (Leblanc and Rao
B. Balabanova et al.
by the type of soil, pH value, as well as the content of organic matter in the soil
(Stankovic et al. 2018). Representing parts of some enzyme complexes and proteins, essential heavy metals are necessary for normal plant growth and development. However, the mentioned accumulation of heavy metals can be a consequence
of binding to SH groups of proteins and result in inhibition of enzyme activity, disruption of their structure, deficiency of essential metals, and stimulation of production of free radical species, causing oxidative stress (De Miguel et al. 1999).
Accumulation of heavy metals causes inhibition of growth of aboveground and
underground parts, reduction of seed germination, reduction of photosynthetic pigments, formation of chlorosis and leaf necrosis, and loss of turgor, which is related
to accelerated aging and death of the plant itself. Toxic metals lead to changes in the
structure of plant tissue and biochemical and molecular processes (Jӓrup 2003).
5.2.4 The Effects of Heavy Metals on Bryophytes
Though growth and development are commonly used parameters for the assessment of the heavy metal toxicity in plants, negative effects of heavy metal pollution could be detected before the alteration of these two parameters become
obvious (Wolterbeek 2002). These effects include ultrastructural changes as well
as the changes in the plant physiological processes and characteristics (Stankovic
et al. 2018). Ultrastructural changes seen in bryophytes under heavy metal stress
are evident (Stankovic et al. 2018). Along with the ultrastructural changes, heavy
metals may also disrupt various metabolic processes. These negative effects could
be explained by the high affinity of heavy metals for sulfhydryl groups in various
proteins (Boquete et al. 2014; Stankovic et al. 2018). The chlorophyll content can
be also used as a tracking signal for assessment of the physiological state and
biochemical functionality of plant organism (Nagajyoti et al. 2010). However,
there have not been many studies investigating the relationship between the presence of different heavy metals in bryophytes and the chlorophyll concentration
(Stankovic et al. 2018).
5.2.5 Intracellular and Surface-Bound Fractions of Elements
Just like other terrestrial plants, mosses have adapted to life on land: the waxy cuticle is a protection against dehydration, gas exchange takes place through the coup,
and their zygote remains protected within the female sexual organ (archegonia)
developing into a multicellular embryo. Mosses with terrestrial plants share some
other significant features: they are parenchymal structures, and their life cycle
consists of heteromorphic and heterophase generation change (Leblanc and Rao
B. Balabanova et al.