Cold Tolerance in Rice

RICE: (Oryza sativa L.)

FAMILY: Gramineae (Poaceae)

Chromosome no. : 2n=24

Area and production in world=

161.2 million ha, 480.01 million tonnes

Area and Production in India=

44.5 million ha, 106.5 million tonnes

Area and Production in J&K=

1.41 lakh ha, 3.72 lakh tonnes

IRRI, 2016

www.indiastat.com

Major types of stresses in rice

Blast

Bacterial Leaf Blight

Brown

Spot

Brown Plant

Hopper

Cold

Heat

Salinity

Drought

Biotic Abiotic

Stress: An adverse force or a condition, which inhibits the normal functioning and well being of a biological system such as plants . (Jones et al., 1989)

Cold stress is the big issue in temperate world faced by rice crop

Chilling stress – when plants are exposed to a low temperature from 0 -15 ºC

Freezing stress – when plants are exposed to a low temperature below 0 ºC Zhang et al., 2014

Cold stress tolerance: Ability of a plant to survive /perform better under low

temperature is called as cold stress tolerance. (Sanghera et al., 2011)

Growth stage Critical temperature ( )℃

Type of cold injury

Germination 10 Poor, delayed

Seedling 13 Retarded seedling growth Leaf discoloration, seedling rot

Vegetative 15 Inhibited rooting, growth and tillering

Delayed panicle initiationReproductive 17 Inhibited panicle development

Degenerated spikeletsDisturbed meiosis and pollen

formationHeading 17 Poor panicle exsertion

Inhibited anther dehiscence and pollination

Maturity 14 Poor grain filling and quality Early leaf senescence

Type and symptoms of cold damage in rice

(Basuchaudhuri, 2014)

Comparison between cold stressed and normal rice plant

Normal Stressed

Normal Stressed

(Yadav, 2010)

Evaluation criteria

Description Temperature & duration

Reference

Germination stageVigor ofgermination

Vigor of germination (%) = Number of germinated grains/Number oftotal grains × 100

14°C/7-17 d Han et al., 2006

Seedlingsurvival rate

Seedling survival rate (%) = Surviving seedlings/Sprouting seeds ×100

2°C/3 d Zhou et al., 2012

Seedling stageSurvival rate

Number ofsurviving plants/Total number of plants treated × 100

4°C/6 d Zhang et al., 2011

Leafemergence

New leaf emergence demonstrates maintained vigor and increasedgrowth.

4°C/7 d Xie et al., 2012

Methods of evaluation of cold stress

Evaluation criteria

Description Temperature & duration

Reference

Reproductive stageSpikeletfertility(CGC)

Spikelet fertility is calculated as the ratio of filled grains to the totalnumber of spikelets based on cold greenhouse cultivation

12°C/6 d Sato et al., 2011

Spikeletfertility (CDWI)

Spikelet fertility is calculated as the same as spikelet fertility (CGC),but the cold treatment is based on cold deep-water irrigation.

18-19°C/~60 d

Shirasawa et al., 2012

Methods of evaluation of cold stressCont…

COLD TOLERANCE SCREENING

Xie et al.,2014

COLD TOLERANCE SCALE

Xie et al., 2014

Changes in metabolic properties of rice plant during cold stress

Group & property Effect on tolerance Relevant gene Reference

Electrolyte leakage Negative CBF1/DREB1b, OsLti6

Zhang et al. 2011

ROS & MDA

Hydrogen peroxide Negative OsAPXa, OsMKK6, OsMPK3

Xie et al. 2012

Superoxide radicals Negative OsAPXa Sato et al. 2011

Hydroxyl radicals Negative OsAPXa Sato et al. 2011

Malondialdehyde Negative OsAPXa, OsMKK6, OsMPK3

Xie et al. 2012

ROS= Reactive oxygen species

Changes in metabolic properties of rice plant during cold stress

Group & property Effect on tolerance Relevant gene ReferenceChlorophyllcontent

Positive OsiSAP8, TERF2 Tian et al., 2011

Soluble sugarsSucrose Positive OSINV4,

OsDREB1ATian et al., 2011

Hexose Positive OSINV4 Oliver et al., 2005

Raffinose Positive OsDREB1A, TERF2 Tian et al., 2011

Glucose Positive OsDREB1A, TERF2 Tian et al., 2011

Fructose Positive OsDREB1A, TERF2 Tian et al., 2011

Trehalose Positive OsNAC5, OsPP1, Song et al., 2011

Cont…

Changes in metabolic properties of rice plant during cold stress

Group & property Effect on tolerance Relevant gene ReferenceCold related amino acids

Proline Positive OsCOIN, OsDREB1A, OsMYB2, OVP1

Huang et al., 2009; Tian et al., 2011

AntioxidantsAscorbic acid Positive Unknown Kim and Tai, 2011

Glutathione Positive OsTRX23 Kim and Tai, 2011

Cont…

Zhang et al. Rice. 2014, 7:24http://www.thericejournal.com/content/7/1/24

Mechanism of cold stress tolerance

Mahajan & Tuteja, 2005

General overview of signal transduction pathwayJanska et al. 2014

QTLs RELATED TO COLD TOLERANCE AT THE GERMINATION STAGE

QTLs analysis for low-temperature germinability revealed that multiple genes control this trait.

Two QTLs controlling low-temperature germinability from a cross between a vigorous and a weak low-temperature germinability cultivars .

(Fujino et al. 2004)

Growth stage QTL name Chromosomal location

Evaluated trait

Reference

GerminationqLTG-4-1 4 Germination

rate at 15℃Miura et al., 2001

qLTG-3-1 3 Germination rate at 15℃

Fujino et al., 2004qLTG-3-2 3

QTLs RELATED TO COLD TOLERANCE AT VEGETATIVE STAGE

Growth stage QTL name Chromosomal location

Evaluated trait

Reference

Vegetative qSCT-11 11 Survival rate

after 13 days at 10℃

Zhang et al., 2005

qSCT-1 1 Survival rate after 7 days

at 6℃

Jiang et al., 2008

qCTS-2 2 Survival rate after 7 days

at 6-10℃

Lou et al., 2007

qCTss11 11 Survival rate after 6 days

at 4℃

Koseki et al., 2010

qCTS-4-1 4 Survival rate after 7 days

at 6-8℃

Andaya &Tai, 2006

QTLs RELATED TO COLD TOLERANCE AT REPRODUCTIVE STAGESaito et al. (2001) detected two closely linked QTLs (Ctb-1 and Ctb-2) for cold tolerance and suggested their association with anther length.

Growth stage QTL name Chromosomal location

Evaluated trait

Reference

ReproductiveqCtb-1 4 Anther length Saito et al.,

2010

Ste1& Ste2 1 Spikelet fertility

Lie et al., 2003

qCT-7 7 Spikelet fertility

Takeuchi et al., 2001

qCTB-8 8 Seed fertility Kuroki et al., 2007

qLTB-3 3 Seed fertility Shirasawa et al., 2012

A case study:

Material & Methods:

•Twenty nine rice varieties were used in this study, 5 belonging to japonica and 24 to indica subspecies

•Seeds were subjected to two different temperatures: Cold treatment- 14℃ Normal- 28 ℃

Germination percentage and germination energy at two treatments

Results/ Findings:

Germination percentage (%)

Varieties Response to cold stress

0-33 Taibonet, Sharm, Izumrud, PakLi ,Snezhinka, EI 293, Kurchanka and Liman

Sensitive

34-66 Avangard, Akdala, Altynay, Anait, Aral 202, Aru, Bakanasski, Madina, Marzhan, Opytnoe, Solnechnyi, Yantar, Jinbubyeo & Odaebyeo

Moderately tolerant

67-100 KazNIIR-5, Kuban-3, Lazurnyi, Lider, Novator, UzRos7-13 and Fisht

Tolerant

Transgenic approach

Gene(s) Cold treatment/ Plant age or stage

Characteristics of transgenic lines Reference

OsDREB1 and AtDREB1 2°C for 4 days/17 days old

Higher survival rates (up to 90%) under low temperature as compared to WT lines. Elevated contents ofosmoprotectants such as free proline and various soluble sugars

Ito et al.(2006)

OsDREB1F 10°C for 7 days/16 days old

Enhanced tolerance to low temperature

Wang et al.(2008)

ZmCBF3 4°C for 1 day/21 days old

Transgenic lines showed a remarkable increase in survival rates (ranging from 67% to 93%) when compared with WT plants (32%) under cold treatment.

Xu et al.(2011)

OsCOIN 4°C for up to3.5 days/14 daysOld

Enhanced cold tolerance (up to 76% survival,compared to 52% survival in WT plants

Liu et al.(2007)

OsZFP245 4°C for 4 days/four-leaf stage

High tolerance to cold (~80%survival, compared to 20% survival in WT plants). Increased proline levels

Huang et al.(2009)

Available reports on generation of cold-tolerant rice plants by genetic transformation

Gene(s) Cold treatment/ Plant age or stage

Characteristics of transgenic lines Reference

SNAC2 4°C for 5 days/four-leaf stage

Significantly enhanced cold tolerance (after 7 days of recovery, more than 50% of the transgenic plants remained vigorous while almost all WT plants died

Hu et al.(2008)

OsNAC5 4°C for 6 days/14 days old

Enhanced tolerance to cold (~70% survival, compared to 50% survival in WT plants. Reduced accumulation of malondialdehyde and H2O2

Song et al.(2011)

OsMYBS3 4°C for 7 days/10 days old

Enhanced cold tolerance (up to 86% survival, compared to 10% survival in WT plants)

Su et al.(2010)

TaWFT1 and TaWFT2 5°C for 11 days/10 days old

Enhanced cold tolerance (up to almost 90% survival, compared to fewer than 10% survival in WT plants

Kawakamiet al.(2008)

OsTPS1 4°C for 5 days/14 days old

Enhanced tolerance to cold (up to 90% survival, compared to 4% survival in WT plants),

Huang et al.(2009)

Available reports on generation of cold-tolerant rice plants by genetic transformation

• New cold-tolerant cultivars will need to be designed according to the growth stage

when plants will be exposed to cold in a particular region.

• Identification and use of cold tolerant donor parents.

• A deeper understanding of the transcription factors and the major stress-responsive

genes is required.

• Improvement of screening techniques.

• Research is needed for a better understanding of the relationships among tolerances

at different growth stages.

• Modified cultural practices must be innovated to alleviate damage.

• International cooperation and collaboration.

Future directions

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