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Role of Hydropriming and Magneto-Priming in Developing Stress Tolerance

with metabolites, proteins, antioxidants, membrane lipids, stress-related

transcription factors, regulatory factors, etc. (Kai & Iba, 2014).

Temperature raised above ambient temperature by 10–15°C results in

heat shock and harms the growth, development, and production of plants

(Hall, 2001) This involves, denaturation of proteins, inhibition of enzymes,

alteration of membrane integrity (Howarth, 2005), physiological process,

root, and shoot inhibition, moisture content, seed, and tiller size (Iqbal et

al., 2017), reduced photosynthesis and respiration (Barnabás et al., 2007),

abscission and senescence (Hasanuzzaman et al., 2013; Vollenweider &

Günthardt-Goerg, 2005). It also alters the gene expression levels, accu­

mulation of transcripts and initiates stress response by synthesis of genes

involved in stress response (Iba, 2002). Low temperature or chilling stress

also has harmful effects by interfering in the normal functioning of plants

systems. However, plants induce different mechanisms to overcome stress

by making short- and long-term alterations in molecular, and morphological

mechanisms, i.e., leaf orientation, membrane composition, transpiration, etc.

(Adam et al., 2011). Pre-treatment of seeds can be beneficial to increase toler­

ance against thermal stress (Nascimento et al., 2021). This is done by seed

priming that promotes protein synthesis for HSPs, and enzymes required for

tissue repair such as L-isoaspartyl, methyltransferase, etc., to increase low

and heat temperature stress tolerance (Ji et al., 2017; Kester et al., 1997).

Various studies have reported germination under cold stress with improved

crop yield in hydroprimed maize (Finch-Savage et al., 2004) and resulted in

faster germination of chickpea (Elkoca et al., 2007). Hydropriming could

alleviate the negative impact of cold temperature on the plant performance

in Mungbean and narrow-leaf lupine (Lupine angustifolius) (Płażek et al.,

2018; Posmyk & Janas, 2007). It was shown that resistance to chilling can

be improved better seed hydration (Knypl, 1979; Posmyk & Janas, 2007),

possibly due to changes in membrane conformation (Chen & Arora, 2013).

4.4 CONCLUSIONS

Uncertain and adverse environmental conditions during sowing compel the

farmers to use high seed rate to compensate for poor emergence and achieve

a normal crop stand. Seed priming is a well-recognized seed enhancement

technique to enhance the planting value of various crops as it improves the

seed performance under suboptimal sowing conditions. It induces morpho­

logical adaptations accompanied by physiological, biochemical, and molecular

changes in plant cells under environmental stresses (Figure 4.1). Morphological