Mineral nutrition in pLANTS
Channel: ISHTA’s BIO ACADEMY
Date: 2022-10-19

Plants obtain their inorganic nutrients from air, water and soil. Plants absorb a
wide variety of mineral elements. Not all the mineral elements that they absorb are
required by plants. Out of the more than 105 elements discovered so far, less than
21 are essential and beneficial for normal plant growth and development. The
elements required in large quantities are called macronutrients while those required
in less quantities or in trace are termed as micronutrients. These elements are
either essential constituents of proteins, carbohydrates, fats, nucleic acid etc.,
2015-16(19/01/2015)
MINERAL NUTRITION 205
and/or take part in various metabolic processes. Deficiency of each of these
essential elements may lead to symptoms called deficiency symptoms. Chlorosis,
necrosis, stunted growth, impaired cell division, etc., are some prominent deficiency
symptoms. Plants absorb minerals through roots by either passive or active
processes. They are carried to all parts of the organism through xylem along with
water transport.
Nitrogen is very essential for the sustenance of life. Plants cannot use
atmospheric nitrogen directly. But some of the plants in association with N2
-fixing
bacteria, especially roots of legumes, can fix this atmospheric nitrogen into
biologically usable forms. Nitrogen fixation requires a strong reducing agent and
energy in the form of ATP. N2
 -fixation is accomplished with the help of nitrogenfixing microbes, mainly Rhizobium. The enzyme nitrogenase which plays an
important role in biological N2
 fixation is very sensitive to oxygen. Most of the
processes take place in anaerobic environment. The energy, ATP, required is
provided by the respiration of the host cells. Ammonia produced following N2
 fixation
is incorporated into amino acids as the amino group