Rice intermediate filament, OsIF, stabilizes photosynthetic machinery and yield under salinity and heat stress

Abstract

Cytoskeleton plays a vital role in stress tolerance; however, involvement of intermediate filaments (IFs) in such a response remains elusive in crop plants. This study provides clear evidence about the unique involvement of IFs in cellular protection against abiotic stress in rice. Transcript abundance of Oryza sativa intermediate filament (OsIF) encoding gene showed 2–10 fold up-regulation under different abiotic stress. Overexpression of OsIF in transgenic rice enhanced tolerance to salinity and heat stress, while its knock-down (KD) rendered plants more sensitive thereby indicating the role of IFs in promoting survival under stress. Seeds of OsIF overexpression rice germinated normally in the presence of high salt, showed better growth, maintained chloroplast ultrastructure and favourable K+/Na+ ratio than the wild type (WT) and KD plants. Analysis of photosynthesis and chlorophyll a fluorescence data suggested better performance of both photosystem I and II in the OsIF overexpression rice under salinity stress as compared to the WT and KD. Under salinity and high temperature stress, OsIF overexpressing plants could maintain significantly high yield, while the WT and KD plants could not. Further, metabolite profiling revealed a 2–4 fold higher accumulation of proline and trehalose in OsIF overexpressing rice than WT, under salinity stress.

Morphological and physiological factors contributing to early vigor in the elite rice cultivar 9,311

“…Higher yield, higher resource use efficiency, higher stress tolerance, and better quality are major goals for future rice breeding [53][54][55][56] . However, the physiological and architectural features of rice plants that are crucial for realizing these goals are still far from being fully understood 5,57 .…”

A unique bZIP transcription factor imparting multiple stress tolerance in Rice

“…It was found that OsHBP1b over-expressing single copy lines possess 4–5 fold higher expression of OsHBP1b transcript (Additional file 1: Figure S1) confirming the transgene functionality. It is well known that even though the response of plants towards abiotic stress is a multigenic trait, salt tolerant transgenic plants could be developed by introducing a single gene (Singla-Pareek et al 2001; Tripathi et al 2016; Soda et al 2018). Published literature has also shown that the plants ectopically-expressing bZIP transcription factors exhibit a positive effect on their growth, development and salinity tolerance (Gao et al 2011; Liu et al 2014; E et al 2014; Lakra et al 2015).…”

Harmonizing technological advances in phenomics and genomics for enhanced salt tolerance in rice from a practical perspective

“…In a study based on the diversity panel of 306 rice accessions involving HD 700 K has revealed 1900 significant SNPs and ~ 2300 candidate genes involved in rice salinity tolerance. This study clearly dissected a well-known major QTL, Saltol-1 associated with shoot Na/K ratio located on chromosome 1 (~ 9.3 Mb – 16.4 Mb) (Bonilla et al 2002; Soda et al 2013) having its key candidate gene, OsHKT1; 5 (positioned at 11.45 Mb) which controls sodium ion uptake in xylem (Ren et al 2005).…”

“…Subsequently, SALTOL was deeply characterized through linked SSR markers flanking the QTL region (Thomson et al 2010). Another study revealed that within SALTOL QTL region in the Pokkali variety, precise salinity induced factors (SIFs) were found expressed which could be putatively associated with vegetative growth, fertility, viability and early flowering under salinity stress (Soda et al 2013).…”