The document outlines strategies for developing drought-smart future crops. It discusses omics tools like genomics, transcriptomics, proteomics, and metabolomics that can be used to identify genes and pathways related to drought tolerance. Transgenic approaches like genetic engineering can introduce drought tolerance genes. Conventional breeding and speed breeding can combine traits from parental lines. Integrating these modern techniques with traditional methods like agronomic practices can help develop crops with improved drought resistance and yield stability under water scarcity. A case study identifies genomic loci, genes and transcription factors in maize affecting seminal root length under drought. Future work may combine genome editing, phenomics and speed breeding to rapidly deliver climate-smart crops.

1. VENUGOPAL GOWDA R
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2. 1. WHAT IS DROUGHT STRESS ?
2. WHY DO WE NEED DROUGHT-SMART FUTURE CROPS ?
3. WHAT ARE THE DIFFERENT KINDS OF CROPS RESPONSE TO
DROUGHT-STRESS?
4. HOW DROUGHT-STRESS TO DROUGHT-SMART CROPS
5. CASE STUDY
6. CONCLUSION
7. FUTURE OUTLOOK
8. REFRENCES
OUTLINE

3. DROUGHT STRESS(DS): “Drought stress is a condition in which
a prolonged or severe deficiency of water (moisture) limits the
normal growth, development, and productivity of plants,
ecosystems, or agricultural systems”.
(Ansari et al., 2019)
DROUGHT-SMART FUTURE CROPS: They are the plant varieties
that have been obtained by combination of advanced phenotyping,
molecular breeding and genetic engineering approaches which exhibits
enhanced tolerance or resistance to drought conditions.
(Cheng et al., 2021)
WHAT IS DROUGHT STRESS

4. READY-TO-GROW FUTURE CROP:
where crops are designed or engineered to be more resilient,
productive, and adaptable to changing environmental conditions,
thus being "ready to grow" in various circumstances and future
agricultural challenges.
(Raza et al., 2023)

5. (http://www.fao.org/giews/earthobservation/index.jsp)
WHY WE ARE TALKING ABOUT DROUGHT-SMART AND
READY TO GROW FUTURE CROPS?

6. ABIOTIC
STRESS
• Drought (water
stress)
• Water logging(excessive
watering)
• Extreme temperature
• Salinity and mineral
toxicity
BIOTIC
STRESS
• Bacteria
• Virus
• Fungi
• Nematodes
• Weeds
• Insects etc.
WHAT ARE THE DIFFERENT TYPES OF STRESS ?

7. Plant
species
Stress condition Experiment
al condition
Effect References
GROWTH
Barley 40% water
holding
capacity(WHC);
6month
Field Average plant height
reduced by 20%
Hellal et al.,
(2019)
Chickpea 70% field
capacity;30 days
Field Reduced germination
rate by 40%
Mahmood et
al ., (2019)
wheat 25% field
capacity; 21day
Pot Reduced shoot &
grain mass by 30-40%
Mickky et
al.,(2020)
Tomato 33% field
capacity; 4month
Field Reduced average fruit
weight by 78%
Cui et al.,
(2020)
Rice 30% field
capacity; 4-5
month
Pot Reduced plant height
by 26%
Tefera et al.,
(2021)
Maize 50% field
capacity
Pot Reduced plant height
by 38%
Shemi et al .,
(2021)
Table 1 : Growth reduction in various crop plants under drought stress

8. Plant
species
Stress condition Experiment
al condition
Effect References
YIELD
Maize 50% field
capacity; 15days
Greenhouse Reduced 100-kernel
weight and yield by
85%
Hussain et
al., (2019)
Rice Withholding
water; 60days
Field Reduced plant yield by
28%
Yang et al .,
(2019)
Rice Withholding
water; 14days
Field Reduced plant yield by
~50%
Melandri et
al.,(2020)
Potato PEG8000; 21days Growth
room
Reduced average plant
yield by 90-95%
Handayani
et al., (2020)
wheat Aminoacid at 3 ml
/L; 7days
Field trial Reduced grain yield by
3.4%
Haider et al.,
(2021)
Maize 50% field
capacity; 10-
20days
Pot
experiment
Reduced grain yield by
30%
Shemi et al
., (2021)
Table 2 : Yield reduction in various crop plants under drought stress

9. MORPHO-
PHYSIOLOGICAL
CHANGES
 Reduced leaf
surface area
 Reduction in plant
height
 Reduced
chlorophyll
 Low stomatal
conductance
 Low transpiration
and low biomass
 Loss in fresh or dry
biomass
ROOT ARCHITECTURE
ADJUSTMENT
 Changes in root length
 More root surface area
 Narrowing of root angle
 Greater root density
WHAT ARE THE DIFFERENT KINDS OF CROPS RESPONS TO
DROUGHT-STRESS?
OXIDATIVE
DAMAGE
• Accumulation of
free radicals/
reactive oxygen
species(ROS)
• Synthesis of
enzymes such as
gluthione
reductase
• Oxidation of
lipids, DNA, RNA

10. WHAT ARE THE DIFFERENT KINDS OF CROPS RESPONSE
TO DROUGHT-STRESS?
OSMOTIC
ADJUSTMENTS
• Increase in total
sugar content
• Synthesis of
osmolytes, such
as proline,
betaines, sugar
alcohols,
organic acids
YIELD LOSS
 Decreased grain
fillings(cereals)/po
ds(soya bean)
 Poorly developed
pods(soya bean)
 Reduced seed
weight
 Reduced seed
number
 Decline in seed
quality

11. THROUGH
DIFFERENT
STRATEGIES
TO BREED
DROUGHT
SMART
DROUGHT SMART
DROUGHT SUSCEPTIBLE
HOW DROUGHT SMART CROP DEVELOPED ??
(Hina et al., 2021)

12. VARIOUS
STRATEG
IES
1.OMICS TOOLS
5.BIOCHEMICAL
AND
MECHANICAL
OPTIONS
4.CONVENTIONA
LAPPROACHES
3.MODERN
BREEDING
PLATFORMS
2.TRANSGENIC
APPROACHES
VARIOUS STRATEGIES TO BREED DROUGHT-
SMART CROPS

13. 1. OMICS TOOLS
1
2
3
4
5

14. • Genomic-Assisted Breeding (GAB), also known as Genomic
Selection (GS), that integrates genomics and genetics.
• Trait Identification- through genome-wide association studies
(GWAS) or Quantitative trait loci (QTL) mapping.
• QTL mapping offers genetic insight into physiological and agronomic
traits in the biparental population under drought stress.
• Genome-wide association studies (GWAS) can identify contributory
alleles for specific traits that can be used to develop DS-tolerant crop
plants.
A. GENOMIC-ASSISTED BREEDING (GAB) FOR DROUGHT
TOLERANCE

15. (Nitika et al., 2021)

16. • Transcriptomics is the study of the transcriptome. It involves
techniques to identify, quantify, and analyze the RNA molecules
expressed under different conditions.
• Transcriptomics study for drought tolerance involves sample collections
-under well-defined drought stress conditions. mRNA is extracted from
the collected plant samples and subjected to mRNA sequencing.
• In data analysis, Differential expression analysis compares gene
expression levels between upregulated or downregulated in response to
drought stress and identifying the candidate gene.
B. TRANSCRIPTOMICS

17. (Fatima et al., 2022)

18. • Proteomics is the study of the proteome, encompassing the
identification, quantification, and functional characterization of
proteins. It aims to understand how the expression and activity
of proteins change in response to stressors like drought.
• The extracted protein is analyzed in mass spectrometer. It
identifies which proteins are upregulated or downregulated
during drought , specific proteins that act as biomarkers for
drought stress, and researchers can target specific proteins or
pathways for genetic manipulation, breeding,
C. PROTEOMICS

19. (Kristyna et al., 2021)

20. • Metabolomics has largely focused on the organic molecular
compounds (metabolites) and the related biochemical changes
found in or produced by organisms and their tissues and cells .
• It is provides an insights into the metabolic pathways and
compounds involved in the drought adoption.
• Various techniques are used to analyze the metabolites which
includes mass spectrometry, nuclear magnetic resonance etc.,
then data analysis and validation of specific metabolites.
D. METABOLOMICS

21. • The metabolome data can be used in future studies such as
Quantitative Trait Locus (QTL) or Genome-Wide Association
Studies (GWAS) to discover genetic loci or specific genes linked to
these metabolic traits, facilitating the development of gene-specific
markers for crop improvement

22. • Epigenetics is a branch of genetics that studies heritable changes in
gene expression or cellular phenotype caused by mechanisms other
than alterations in the DNA sequence.
• Various techniques employed to analyze the epigenetic changes
associated with DS, which involve DNA methylation, histone
modifications et.,
E. EPIGENETICS

23. (Saeed et al., 2022)

24. (Zhou et al., 2022)

25. • Transgenic breeding, also known as genetic engineering,
involves the introduction of specific genes from one organism
into the genome of another organism to confer a desirable
traits.
• Gain of function and gene-knock-down approaches, such as
RNAi and CRISPR/cas9, have yielded valuable information on
how complex gene networks regulate dehydration stress
physiology.
2. TRANSGENIC APPROACHES

26. (Kumar et al., 2023)

27. • Conventional breeding generally takes 8–10 year to generate
a new variety.
• Speed breeding (SB) techniques which allow breeders to
advance the crop generation in a shorter period of time
(Samantara et al., 2022)
3. SPEED BREEDING:

28. (Ahmad et al., 2021)
(Saxena et al., 2021)

29. (Raza et al., 2023)

30. • Conventional breeding identifies parental lines with desirable
traits to generate a favorable combination of the new line for
the next generation.
• Comparing a large set of cultivars makes identifying the best
ones with desirable traits under water-scarce conditions easier
than using a small set.
• However, breeding for drought tolerance mainly depends on
the yield potential of parental lines rather than tolerance-
related traits.
4. CONVENTIONAL BREEDING

31. • Phytohormones including
auxins, gibberellic acid,
cytokines, ABA, ethylene,
jasmonic acid (JA),
strigolactones, and
brassinosteroids are signal
molecules and essential
components for regulating
plant growth under DS.
a. Phytohormone applications
5. BIOCHEMICALAND MECHANICAL OPTIONS FOR
DROUGHT MANAGEMENT

32. B. AGRONOMIC PRACTICES
• Agronomic practices, such as water management, adjusting plant density, and
nutrient management, are the backbone for increasing crop production under
seasonal DS.
• Applying gypsum is important for soils with low infiltration capacity. Other
strategies include zero tillage, mulching, intercropping, and deep plowing.
C .PLANT DENSITY AND TIME OF SOWING
• Sowing date is important for mitigating the devastating effects of DS at the
reproductive stage.
• Early sowing of maize avoids the potential drought and high temperatures in
mid-summer.
• Increasing plant density- high plant density of maize crop decreases leaf area
index, thus reducing evapotranspiration and enhancing WUE under arid
conditions.

33. (Raza et al., 2023)

34. CASE STUDY

35. • The goal of there study was to identify genomic loci and
candidate genes affecting SRL under drought conditions for
improving drought tolerance breeding in maize.
• Plant materials and growth conditions: A natural population
including 209 diverse accessions of maize inbred lines was
used for measuring the shoot dry weight (SDW), primary root
length (PRL), seminal root length (SRL), and seminal root
number (SRN) under well-watered (WW) and water-stressed
(WS) conditions.
MATERIALS AND METHODS

36. • Phenotypic identification and statistical analysis:
• RNA sequencing and data analysis:
• Genome-wide association study:
• Quantitative real-time PCR:

39. Differentially expressed genes (DEGs) in eight genotypes in response to drought stress.
The number of upregulated, downregulated and TF-coded DEGs of the eight genotypes are given.

42. • Identifying new key genes and QTL, metabolites, and proteins related to
DS-responsive mechanisms can be a potential candidate for CRISPR/Cas-
mediated genome editing, combined with speed breeding could be used to
develop new DS-tolerant cultivars.
• to achieve ‘zero hunger’ goal and feed the growing population.
• Combining a variety of traditional and modern biotechnological techniques
will significantly improve our current understanding of DS responses and
tolerance mechanisms in crop plants.
CONCLUSION

43. • Millets can be crops of choice to transfer the
beneficial attributes to other crop relatives..
• The deployment of genome editing with speed
breeding and phenomics can help in fast-track crop
breeding.
• The advent of high-throughput genomics and
phenomics- producing climate-smart crops to
overcome food security challenges in the future.
FUTURE OUTLOOK

44. 1. Ansari, F. A., & Ahmad, I. (2019). Isolation, functional characterization and efficacy
of biofilm-forming rhizobacteria under abiotic stress conditions. Antonie Van
Leeuwenhoek, 112, 1827-1839.
2. Raza, A., Mubarik, M. S., Sharif, R., Habib, M., Jabeen, W., Zhang, C., ... &
Varshney, R. K. (2023). Developing drought‐smart, ready‐to‐grow future crops. The
Plant Genome, 16(1), e20279.
3. Xu, K., Zhao, Y., Zhao, Y., Feng, C., Zhang, Y., Wang, F., ... & Li, H. (2022).
Soybean F-box-like protein GmFBL144 interacts with small heat shock protein and
negatively regulates plant drought stress tolerance. Frontiers in plant science, 13,
823529.
4. Guo, J., Li, C., Zhang, X., Li, Y., Zhang, D., Shi, Y., ... & Wang, T. (2020).
Transcriptome and GWAS analyses reveal candidate gene for seminal root length of
maize seedlings under drought stress. Plant Science, 292, 110380.
5. Samantara, K., Bohra, A., Mohapatra, S. R., Prihatini, R., Asibe, F., Singh, L., ... &
Varshney, R. K. (2022). Breeding more crops in less time: A perspective on speed
breeding. Biology, 11(2), 275.
6. Saeed, F., Chaudhry, U. K., Bakhsh, A., Raza, A., Saeed, Y., Bohra, A., & Varshney,
R. K. (2022). Moving beyond DNA sequence to improve plant stress
responses. Frontiers in Genetics, 13, 874648.
References