172
lenthionine. A total of 7 ggt and 5 Csl encoding genes have been reported in the
genome of L. edodes (Chen et al. 2016). Across 26 fungi, in general 2–4 ggt genes
have been identified. Comparatively, high number of ggt genes revealed better ability of L. edodes in catalyzing lentinic acid to L-cysteine sulfoxide derivative. The
C-S lyase genes were found to be a novel cysteine desulfurase (EC 2.8.1.7) with
cysteine sulfoxide lyase activity (Chen et al. 2016).
In another study, de novo assembly performed using paired-end short reads and
long reads and transcriptome sequencing (RNA-seq) predicted 12,959 genes from
the life cycle of L. edodes. It was also found that shiitake lacks genes for lignin
peroxidase. Further, genes involved in the postharvest fruiting body degradation of
fruiting bodies using transcriptome and serial analysis of gene expression (SAGE)
analysis identified upregulation of cell wall hydrolysis-related genes such as glycosyl hydrolase (GH) families GH5, GH16, GH30, GH55, and GH128; thaumatin-like
proteins; chitinases of GH18 and GH20; as well as putative chitosanase of GH75,
during the autolysis of fruiting body. Besides this, several putative transcription factors including high-mobility-group domains, zinc finger domains, and cell deathrelated proteins were found upregulated during postharvest. Therefore, genes
identified for their role in fruiting body autolysis can be targeted for the breedingimproved strains with better fresh life (Sakamoto et al. 2017).
10.6 Nutraceutical Importance
The shiitake mushrooms are consumed as foods and medicine in Asia over
2000 years. The edible mushrooms are rich source of polysaccharides, proteins,
terpenoids, polyphenols, vitamins, and dietary fibers (Moradali et al. 2007;
Asaduzzaman and Mousumi 2012; Reis et al. 2012; Xu et al. 2014). The polysaccharides, proteins, saponins, triterpenes, and flavonoids of edible mushrooms are a
part of healthy foods (Gu et al. 2016). Worldwide, shiitake (L. edodes) is the second
largest cultivated edible mushroom and accounts for approximately 25% of total
edible mushroom production (Jiang 2011). The commercial production of Shiitake
(L. edodes) is available in the USA, Brazil, India, Australia, and Europe (Mason
et al. 2004). The production of shiitake mushroom is over 1,30,000 tons per year,
and 45% of produce is sold fresh. The remaining dried preparation of L. edodes is
available in different forms. The high nutritional value is attributed to the presence
of several bioactive compounds such as lentinan, vitamins (B1, B2, and C), dietary
fibers, ergosterol, niacin, and minerals (Choi et al. 2006). Presently, the shiitake
mushrooms are also consumed in western countries (Liu et al. 2013). Fruit bodies
of L. edodes are composed of 88–92% water, and remaining contents include proteins, lipids, carbohydrates, as well as vitamins and minerals. The mushrooms are a
source of vitamins, provitamin D2 (ergosterol), which under ultraviolet (UV) light
and heat is converted to calciferol (vitamin D2). It also contains vitamin-B complex
including B1 (thiamine), B2 (riboflavin), and B12 (niacin) (Dermiki et al. 2013;
Chen et al. 2015; Poojary et al. 2017). The vitamin such as D although not reported
R. Salwan et al.
lenthionine. A total of 7 ggt and 5 Csl encoding genes have been reported in the
genome of L. edodes (Chen et al. 2016). Across 26 fungi, in general 2–4 ggt genes
have been identified. Comparatively, high number of ggt genes revealed better ability of L. edodes in catalyzing lentinic acid to L-cysteine sulfoxide derivative. The
C-S lyase genes were found to be a novel cysteine desulfurase (EC 2.8.1.7) with
cysteine sulfoxide lyase activity (Chen et al. 2016).
In another study, de novo assembly performed using paired-end short reads and
long reads and transcriptome sequencing (RNA-seq) predicted 12,959 genes from
the life cycle of L. edodes. It was also found that shiitake lacks genes for lignin
peroxidase. Further, genes involved in the postharvest fruiting body degradation of
fruiting bodies using transcriptome and serial analysis of gene expression (SAGE)
analysis identified upregulation of cell wall hydrolysis-related genes such as glycosyl hydrolase (GH) families GH5, GH16, GH30, GH55, and GH128; thaumatin-like
proteins; chitinases of GH18 and GH20; as well as putative chitosanase of GH75,
during the autolysis of fruiting body. Besides this, several putative transcription factors including high-mobility-group domains, zinc finger domains, and cell deathrelated proteins were found upregulated during postharvest. Therefore, genes
identified for their role in fruiting body autolysis can be targeted for the breedingimproved strains with better fresh life (Sakamoto et al. 2017).
10.6 Nutraceutical Importance
The shiitake mushrooms are consumed as foods and medicine in Asia over
2000 years. The edible mushrooms are rich source of polysaccharides, proteins,
terpenoids, polyphenols, vitamins, and dietary fibers (Moradali et al. 2007;
Asaduzzaman and Mousumi 2012; Reis et al. 2012; Xu et al. 2014). The polysaccharides, proteins, saponins, triterpenes, and flavonoids of edible mushrooms are a
part of healthy foods (Gu et al. 2016). Worldwide, shiitake (L. edodes) is the second
largest cultivated edible mushroom and accounts for approximately 25% of total
edible mushroom production (Jiang 2011). The commercial production of Shiitake
(L. edodes) is available in the USA, Brazil, India, Australia, and Europe (Mason
et al. 2004). The production of shiitake mushroom is over 1,30,000 tons per year,
and 45% of produce is sold fresh. The remaining dried preparation of L. edodes is
available in different forms. The high nutritional value is attributed to the presence
of several bioactive compounds such as lentinan, vitamins (B1, B2, and C), dietary
fibers, ergosterol, niacin, and minerals (Choi et al. 2006). Presently, the shiitake
mushrooms are also consumed in western countries (Liu et al. 2013). Fruit bodies
of L. edodes are composed of 88–92% water, and remaining contents include proteins, lipids, carbohydrates, as well as vitamins and minerals. The mushrooms are a
source of vitamins, provitamin D2 (ergosterol), which under ultraviolet (UV) light
and heat is converted to calciferol (vitamin D2). It also contains vitamin-B complex
including B1 (thiamine), B2 (riboflavin), and B12 (niacin) (Dermiki et al. 2013;
Chen et al. 2015; Poojary et al. 2017). The vitamin such as D although not reported
R. Salwan et al.