Salt tolerance in mungbean is associated with controlling Na and Cl transport across roots, regulating Na and Cl accumulation in chloroplasts and maintaining high K in root and leaf mesophyll cells

Md Shahin Iqbal; Peta L Clode; Al Imran Malik; William Erskine; Lukasz Kotula

doi:10.1111/pce.14943

Salt tolerance in mungbean is associated with controlling Na and Cl transport across roots, regulating Na and Cl accumulation in chloroplasts and maintaining high K in root and leaf mesophyll cells

Plant Cell Environ. 2024 May 16. doi: 10.1111/pce.14943. Online ahead of print.

Authors

Md Shahin Iqbal^{1

2

3}, Peta L Clode^{4

5}, Al Imran Malik^{1

2

6}, William Erskine^{1

2}, Lukasz Kotula²

Affiliations

¹ Center for Plant Genetics and Breeding, The UWA School of Agriculture and Environment, The University of Western Australia, Perth, Western Australia, Australia.
² The UWA Institute of Agriculture, The University of Western Australia, Perth, Western Australia, Australia.
³ Pulses Research Center, Bangladesh Agricultural Research Institute, Ishurdi, Bangladesh.
⁴ Centre for Microscopy, Characterisation and Analysis, The University of Western Australia, Perth, Western Australia, Australia.
⁵ School of Biological Sciences, The University of Western Australia, Perth, Western Australia, Australia.
⁶ International Center for Tropical Agriculture (CIAT-Asia), Lao People's Democratic Republic Office, Vientiane, Laos.

PMID: 38757412
DOI: 10.1111/pce.14943

Abstract

Salinity tolerance requires coordinated responses encompassing salt exclusion in roots and tissue/cellular compartmentation of salt in leaves. We investigated the possible control points for salt ions transport in roots and tissue tolerance to Na⁺ and Cl^- in leaves of two contrasting mungbean genotypes, salt-tolerant Jade AU and salt-sensitive BARI Mung-6, grown in nonsaline and saline (75 mM NaCl) soil. Cryo-SEM X-ray microanalysis was used to determine concentrations of Na, Cl, K, Ca, Mg, P, and S in various cell types in roots related to the development of apoplastic barriers, and in leaves related to photosynthetic performance. Jade AU exhibited superior salt exclusion by accumulating higher [Na] in the inner cortex, endodermis, and pericycle with reduced [Na] in xylem vessels and accumulating [Cl] in cortical cell vacuoles compared to BARI Mung-6. Jade AU maintained higher [K] in root cells than BARI Mung-6. In leaves, Jade AU maintained lower [Na] and [Cl] in chloroplasts and preferentially accumulated [K] in mesophyll cells than BARI Mung-6, resulting in higher photosynthetic efficiency. Salinity tolerance in Jade AU was associated with shoot Na and Cl exclusion, effective regulation of Na and Cl accumulation in chloroplasts, and maintenance of high K in root and leaf mesophyll cells.

Keywords: cellular distribution; chloride; cryo‐SEM X‐ray microanalysis; endodermis; mungbean; salinity tolerance; sodium; suberin lamellae.

Abstract

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