Anil Grover

Professor & Head of the Department

Specializations: Rice Heat Stress Biology



Specialization:Rice Heat Stress Biology


Research Interests

Global mean surface air temperature has increased by ~0.5°C in the 20th century and is projected to increase further by 1.5 to 4.5°C in the current century. Global warming is negatively affecting crop yield. My laboratory works on understanding how rice (Oryza sativa L.) plants respond to heat stress at the level of gene expression. Our transcriptome and proteome data suggest that overall the response of rice to heat stress involves signal perception and transduction, activation/synthesis of heat shock factors, genomic and proteomic alterations, ROS metabolism and a host of other proteins associated with biochemical, cellular and physiological processes and with ‘unknown’ functions. One principal way heat affects living systems is through affecting the protein homeostasis. ClpATPases represent a class of molecular chaperones which help in preventing protein aggregation and disaggregating the toxic aggregates formed under stressful regimes. ClpB/Hsp100 proteins are strongly implicated in heat stress biology of diverse organisms. This activity of ClpB/Hsp100 proteins is reportedly mediated with the help of sHsps and Hsp70/Hsp40 proteins. ClpATPase gene family is constituted of 3 ClpB, 4 ClpC and 2 ClpD proteins in rice. Three ClpB of rice include a mitochondrial protein OsClpB-M, a chloroplastic protein OsClpB-P and a cytoplasmic protein OsClpB-C. OsClpB-C, OsClpB-P and OsClpB-M transcripts are strongly induced upon heat stress treatment. In Arabidopsis, we note that a bidirectional promoter is shared between two functionally dissimilar proteins that are involved in a common phenotype of heat tolerance: AtClpB-C which is a chaperone protein and AtCK2 which encodes for the choline kinase enzyme that has a role in plasma membrane synthesis. As in yeast, rice ClpB proteins lack the motif responsible for interaction with ClpP protein and therefore the precise mechanism of their working remains unclear. OsClpB-C, OsClpB-M and OsClpB-P confer partial tolerance to yeast Δhsp104 mutant. OsClpB-C promoter is heat-regulated. 5’UTR of ClpB-C gene appears to have a role in translation process during heat stress. Rice has 23 sHsps genes which include 16 nucleo-cytoplasmic (C) sHsps (9 subfamilies), 3 mitochondrial (M) sHsps (2 subfamilies), 2 endoplasmic reticulum (ER)-localized sHsps, 1 plastidial (P) sHsp and 1 peroxisomal (Px) sHsp having 1 subfamily each.  Most of these genes are heat-regulated. Rice Hsp70 superfamily genes are represented by 24 Hsp70 family and 8 Hsp110 family members. As against 22 DnaJ sequences noted in yeast, rice genome contains 104 J genes. From the complete genome sequence (Rice Annotation release 5), indications are that at least 25 genes constitute OsHsf gene family. From a near complete picture of TA potential of the OsHsf family comprising of 25 members emerging from our studies, it is concluded that the presence or absence of AHA motif is possibly not the only factor determining TA potential of OsHsfs. Our findings will help to identify the transcriptional activators of rice heat shock response. Our recent results show that heat stress regulated OsClpB-C gene expression is controlled by OsHsfA6a, OsHsfB4b and OsClpB-C regulon at the transcriptional level and by 5’UTR sequence at the translational level. We have interest to dissect various components that together constitute response of rice to heat alone and to heat in conjunction with salt, cold, oxidative and flooding stresses.


Selected Publications

  1. LavaniaD, A Dhingra, A Grover. 2018. Analysis of transactivation potential of rice (OryzasativaL.) heat shock factors. Planta (https :// 5-018-2865-2).
  2. Grover A, D Twell and E. Schleiff. 2016. Pollen as a target of environmental changes. Plant Reproduction 29: 1-2. 
  3. Mishra RC, Richa, A Singh and A Grover. 2016. Characterization of 5′UTR of rice ClpB-C/Hsp100 gene: evidence of its involvement in post-transcriptional regulation. Cell Stress Chaperone 21: 271-283 (DOI 10.1007/s12192-015-0657-1).
  4. Mishra RC and A Grover. 2016. ClpB/Hsp100 proteins and heat stress tolerance in plants. Critical Reviews in Biotechnology 36: 862-874.
  5. Mishra RC and A Grover. 2014. Intergenic sequence between Arabidopsis ClpB-C/Hsp100 and choline kinase genes functions as a heat inducible bidirectional promoter. Plant Physiology 166: 1646-1658.
  6. Sarkar NK, Y-K Kim and A Grover. 2014. Coexpression network analysis associated with call of rice seedlings for encountering heat stress. Plant Molecular Biology 84: 125-143.
  7. Mittal D, D Madhyastha and A Grover. 2012. Genome-wide transcriptional profiles during temperature and oxidative stress reveal coordinated expression patterns and overlapping regulons in rice. PLoS ONE 7(7): e40899. doi:10.1371/journal.pone.0040899.
  8. Singh A and A Grover. 2010. Plant Hsp100/ClpB-like proteins: poorly-analyzed cousins of yeast ClpB machine. Plant Molecular Biology 74: 395-404. 
  9. Singh A, U Singh, D Mittal and A Grover. 2010. Genome-wide analysis of rice ClpB/HSP100, ClpC and ClpD genes. BMC Genomics 11: 95.
  10. Sarkar NK, K Yeon-Ki and A Grover. 2009. Rice sHsp genes: genomic organization and expression profiling under stress and development. BMC Genomics 10: 393.
  11. Katiyar_Agarwal S, M Agarwal and A Grover. 2003. Heat tolerant basmati rice engineered by overexpression of hsp101 gene. Plant Molecular Biology 51: 677-686.
  12. Agarwal Manu, Chandan Sahi, Surekha Katiyar-Agarwal, Sangeeta Agarwal, Todd Young, Daniel R Gallie, Vishva Mitra Sharma, K Ganesan and Anil Grover. 2003. Rice Hsp100 protein complements yeast hsp104 mutation by promoting disaggregation of protein granules and shows differential expression in indica and japonica rice types. Plant Molecular Biology 51: 543-553.
  13. Singla SL, A Pareek, AK Kush and A Grover. 1998. Distribution patterns of the 104 kDa stress-associated protein of rice reveal its constitutive accumulation in seeds and disappearance from the just-emerged seedlings. Plant Molecular Biology 37: 911-919.
  14. Pareek A, SL Singla and A Grover. 1995. Immunological evidence for accumulation of two novel 104 and 90 kDa HSPs in response to diverse stresses in rice and in response to high temperature stress in diverse plant genera. Plant Molecular Biology 29: 293-301.
  15. Singla SL and A Grover.  1993. Antibodies raised against a yeast heat shock protein cross-react with a heat and abscisic acid- regulated polypeptide in rice. Plant Molecular Biology 22: 1177-1180