Ismail Cakmak

Sabanci University, Istanbul

Selected Topics in Plant Nutrition

Canola

Soybean

Corn

Thanks

Topics Potassium and Magnesium for better

stem and root growth (and stress tolerance): A new concept ?

Seed Nutrients for better seed vitality and better human nutrition

Potassium in Photosynthesis and Phloem Export

Photosynthetic e-transport, formation of photoassimilates and phloem transport of assimilates are greatly affected by K and Mg nutrition

KMg

PhloemTransport

CO2H2O

O2Sugar

KMg

KMg

K and Mg in PHLOEM TRANSPORTK and Mg plays critical role in phloem transport of sugars

KMg Sugars

KMgKMg

Sugars

Sink

X Mg or K deficiency

Source

(tubers, roots, seeds)

(leaves)

Relationship between sucrose and potassium

concentrations in the expanded leaves of cotton plants

Gerardeaux et al., 2009, Plant Soil

Leaf K, mg g-1

Le

af

Su

cro

se

, m

g g

-1

Accumulation of sugars is also well-known for K- and Mg-deficient leaves

Cakmak et al., 1994b, J. Exp. Bot.

Cakmak, 2013, Plant and Soil

Effect of increasing Mg Supply on shoot and root growth of wheat

Effect of K nutrition on shoot and root growth

Control K Deficiency

Cakmak et al., 1994 J. Exp Bot

Velocity of 13Carbon-transport from leaves in the trunk of field-grown eucalypt trees

0,0

0,5

1,0

with irrigation without irrigation

Ve

loci

ty o

f C

-tra

nsp

ort

(m h

-1)

Adequate K Low K

Epron et al., 2015, Tree Physiol,

Velocity of 13Carbon-transport from leaves in the trunk of field-grown eucalypt trees

0,0

0,5

1,0

with irrigation without irrigation

Ve

loci

ty o

f C

-tra

nsp

ort

(m h

-1)

Adequate K Low K

Epron et al., 2015, Tree Physiol,

Think about K or Mg to make carbon transport faster in plants

Adequate MgLow Mg

Coffea arabica cv. Murta

Picture: Ceylan and Cakmak

Mg Deficiency in Coffee

Adequate Mg

Low Mg

Coffea arabica cv. Murta

Picture: Ceylan and Cakmak

Adequate MgLow Mg

Adequate MgLow Mg

Coffea arabica cv. Murta

Picture: Ceylan and Cakmak

Stem Growth

Kanai et al., 2007 J Exp Bot. 2007

Stem DiameterAdequate K

Low K

Changes in stem diameter of tomato

plants with low and adequate K supply

Stem growth is highly sensitive to low K (more than photosynthesis under low K supply)

Adequate K

Low K

PHOTOSYNTHESIS

STEM DIAMETER

In Tomato Plants

Kanai et al., 2007 J Exp Bot. 2007

Adequate K

Low K

PHOTOSYNTHESIS

STEM DIAMETER

In Tomato Plants

Kanai et al., 2007 J Exp Bot. 2007

Stem growth is highly sensitive to low K

(more than photosynthesis )

0

25

50

75

100

Low K Adequate K

Dry

mat

tre

ral

loca

tio

n (

%) FRUITS

LEAF

STEM

ROOT

Dry matter allocation to fruit, root, stem and leaf parts from 40 to 50 DAE depending on K treatments in cotton plants

Gerardeaux et al 2010, Env. Exp. Bot

80ppm K40ppm K 160ppm K10ppm K5ppm K 20ppm K0ppm K

Growth of maize plants depending on increasing K supply

K Supply

Cakmak et al., 2017, in review

0

4

8

12

16

5 10 20 40 80 160

Tota

l Sh

oo

t D

W(g

pla

nt-1

)

K supply (mg kg-1 soil)

Total shoot dry matter production of 85-days-old maize plants depending on increasing K supply

Cakmak et al., 2017, in review

SHOOT DRY MATTER

0

1

2

3

4

5 10 20 40 80 160

Stem

DW

(gp

lan

t-1)

K supply (mg kg-1 soil)

Stem dry matter production of 85-days-old maize plants depending on increasing K supply

Cakmak et al., 2017, in review

Grain/Fruit Filling and Yield Formation

under Stress

i) Current photosynthesis and

translocation of current

assimilates from leaves

ii) Mobilization of stored Water

Soluble Carbohytrates (WSC)

from stems

Blum et al., 1998; Cassani and Reynolds, 2012

stem reserves

from leaves

maxpixel.freegreatpicture.com/Wheat

Grain filling in wheat and many other crops depends on two major sources of carbon:

If the current photosynthesis is impaired by

stress, such as drought or heat, grain filling

is more dependent on mobilization and

translocation of stored WSC in stem

maxpixel.freegreatpicture.com/

WSC (water solublecarbohytrates) in stem

Stem reserves

10-20 %

Non-Stress Conditions

50-70 %

Stress ConditionsDrought/Heat

Dreccer et al., 2009; Cakmak et al. 2017

Contribution of stem-water soluble carbohydrates (WSC) to final grain yield

10-20 %

Non-Stress Conditions

50-70 %

Stress ConditionsDrought/Heat

Dreccer et al., 2009; Cakmak et al. 2017

Contribution of stem-water soluble carbohydrates (WSC) to final grain yield

Remember K and Mg

Relationship between main stem dry weight and water-

soluble carbohydrate content (WSC) in different wheatcultivars during grain-filling

Ehdai et al 2008, Field Crops Res.

WSC

, mg

Stem Weight, mg

Gang-Ping Xue et al. Plant Physiol. 2008, 146:441-454

Relationships between Stem-WSC concentration and

grain weight or grain yield in different wheat lines.

GRAIN WEIGHT GRAIN YIELD

0,0

0,5

1,0

1,5

0 10 20 30 40 50

Ste

mD

W a

nd

Ste

mW

SC

(g m

ain

sp

ike-1

)

Days of anthesis

Stem DW

Stem WSC

Postanthesis changes in stem dry weight and stem water soluble carbohydrates (WSC) in 11 wheat cultivars

Ehdai et al., 2008 Field Crops Res.

0,0

0,5

1,0

1,5

0 10 20 30 40 50

Gra

inyi

eld

, Ste

mD

W a

nd

Ste

mW

SC (g

mai

n s

pik

e-1

)

Days of anthesis

Grain yield

Stem DW

Stem WSC

Ehdai et al., 2008 Field Crops Res.

Postanthesis changes in stem dry weight, stem water soluble carbohydrates (WSC) and grain yield in 11 wheat cultivars

Blossom without leaves?

Blossom without leaves?

Carbohydrate Translocation from stem/trunk

K, Mg Nutrition???

i) better photosynthesis during post-anthesis(for delivery to grain)

iii) High pool for pre-anthesis reserves

Good K (and Mg) nutrition under stress (such as drought and heat) is required for

ii) phloem transport of assimilates from stems and /or leaves

Cakmak et al., 2017, in review

Carbohydrate storage capacity of stem and translocation of carbohydrates into grain significantly contribute to high yield stability

under stress conditions: K Nutrition!!!!

0

1

2

3

4

5 10 20 40 80 160

Stem

DW

(gp

lan

t-1)

K supply (mg kg-1 soil)

Stem dry matter production of 85-days-old maize plants depending on increasing K supply

Cakmak et al., 2017, in review

0

100

200

300

400

500

600

700

5 10 20 40 80 160

Car

bo

hyd

rate

(mg

pla

nt-1

)

K supply (mg kg-1 soil)

Total amount of stem soluble sugars in 85-days-old maize plants depending on increasing K supply

Cakmak et al., 2017, in review

Novel Fertilizers Targeted Fertilization

Program

focusing on stem nutrition

Conclusion

Seed Nutrients

Yield starts with better seed nutrient density

transitionleytonstone.org.uk

Seed reserves of nutrients represent a key factor

affecting positively seed germination, seedling

emergence and uniformity of the emergence in the

field and final yield of plants.

Well-known positive impact of larger seeds on

seedling vigor and field establishment is often

attributed to higher amount of seed nutrient density.

Today, little attention is, however, paid to the

importance of seed nutrient reserves in practical

agriculture

INTRODUCTION

Published reports indicate that plants need most of their total P requirements (up to 75 %) during their early growth stage.

Very early season P supply is more critical in achievement better yields than the supply of P at later growth stages (Grant et al 2001, Can. J. Plant Sci. 81: 211-224).

These findings highlight importance of seed P-reserves

Seed P-Treatment Low P Soil High P Soil

(mg P g-1 seed)

0 1.23 3.62

15.5 1.63 3.68

46.5 1.88 3.99

77.5 2.24 4.30

(g plant-1)

Effect of seed coating with increasing amount of P (from 0

to 77.5 mg P per gram seed) on shoot dry matter of pearl

millet grown in a P-deficient and P-sufficient soil

Karanam and Vadez, 2010,

Exp. Agric. 46: 457-469

0.0

0.1

0.2

0.3

0 10 50 100

Shoo

t Dry

Wei

ght,

g p

lant

-1

P concentration ofsoaking solution (g L-1)

Shoot dry weight of wheat plants derived from

seeds which were soaked in a solution containing

increasing amount of P

Sekiya and Yano, 2010,

Plant Soil, 327: 347-354

Ideal P-Solution: 50 g K-phosphate per liter (0.35 M K-Phosphate solution)

Enrichment of legume seeds with

phosphorus and molybdenum and yield

Legume plants depending on biological N2 fixation

for their N supply require more P and Mo than plants

receiving fertilizer N, since the reduction of atmospheric

N2 by the nitrogenase system is a very energy-

consuming process, and more Mo and P are needed for

symbiotic N fixation than for general plant metabolism

(Israel, 1987, Plant Physiol, 84:835-840;

“Nodules act as strong sinks of Mo and P”

Grain yield of three common bean cultivars originating from seeds with different concentrations of P and Mo.

(Plants grown under field conditions in Brazil)

Pacheco et al. 2012, FieldCrops Rs. 136: 97-106

Seed enrichment by 2x sprays of 5 kg P ha−1 and 120 g Mo ha−1

Young legume plants also often suffer from obvious

or hidden N deficiency when grown in acidic soils

or in soils with low inorganic N and organic matter.

It is very common that legumes are rarely or at

very low rates fertilized with N because N2-fixation

process provides sufficient N for high yields.

However, N2-fixation system is fully established 4–5

weeks after germination. During this period seed

N reserves might be of great importance.

N Deficiency in Legume Seedlings and

Seed N Reserves

Seed N andSeedling Growth

Relationship between seed N content and seedling dry weight of 16 soybean lines after 27 days of growth

without an external N supply

Naegle et al 2005, Plant and Soil, 271: 329-340

When N supply is adequate

When N supply is inadequate

Dry weight of isogenic soybean seedlings differing in seed N concentrations

Naegle et al 2005, Plant and Soil, 271: 329-340

Low N: 5.5 %; Medium N: 6.3 %; High N: 7.4 %

Seed Boron

Marschner , 2012

Distribution of B within the shoot of canola with increasing B application to the soil.

Boron

Leaves

Seeds

0

500

1000

1500

2000

2500

3000

Low B Soil Adequate B Soil

Gra

in y

ield

(kg

/ha)

Seed-B: 7 ppm Seed-B: 23 ppm

Effect of seed-B and soil-B status on soybean

grain yield under field conditions

Rerkasem et al., 1997, Nutr. Cyc. Agroecosystems, 48: 217-223

Soybean seeds with B concentrations 10 mg B kg-1 have

deformed cotyledons. Seed with 7 mg B kg-1 performed

poorly, with 80% failing to germinate and did not

respond to soil B supply.

Soybean seeds with a low concentration of B have

permanently damaged seed embryos, preventing their

germination or producing defective seedlings.

The critical concentration of B in soybean seed for

permanent damage was between 7 and 10 mg B kg-1,

and for normal seedling development in low B soils was

between 14 and 20.

Seed Zinc

Staining and Localization of Zinc in

Wheat Grain -Dithizone Test

EMBRYO

ENDOSPERM (White flour)

ALEURONE

ALEURONE

Cakmak et al., 2010;

Cereal Chemistry,

77: 10-20

Zinc in Germinating Wheat Seed

Staining Zn

Ozturk et al., 2006, Physiol. Plant. 128:144-152

Zn Concentrations: mg Zn kg–1

Parts emerging from seeds need

very high Zn

Root

Coleoptile

(Red color)

Newly developed radicles (roots) and coleoptile

during seed germination contain up to 200 ppm

Zn (Ozturk et al. 2006, Physiol. Plant.) which

indicates particular roles of Zn during early seed

germination and seedling development.

High seed Zn in seeds acts as a “starter Zn fertilizer”

Candan and Cakmak, unpublished

Role of Seed Zn on Growth of Wheat Plants in a Growth Medium with low Zn supply

Seed-Zn: 9 ppm

Seed-Zn: 20 ppm

0

5

10

15

20

25

30

Zhongyou Narendra CSIRO-I

Sh

oo

t d

ry m

att

er

(mg

pla

nt-

1)

Low seed Zn 21-26 ppm

50-53 ppm

Shoot dry matter production of 3 canola

cultivars with low and high seed Zn

Canola CultivarsSingh and Graham,1997, Plant and Soil, 192: 191-197

High seed-Zn

Source: Ekiz et al., 1998, J. Plant Nutr.

11 mg Zn kgseed-1

45 mg Zn kgseed-1

23 mg Zn kgseed-1

Influence of Seed Zn Content on Growth of Bread Wheat in a Zinc-Deficient Soil in Central Anatolia

PLANT STAND RESULTS –Common Bean from Brazil

Standard Seeds Zn-Enriched seeds

Rashid et al., 2017

Seed Zn: 26 ppm

Seed Zn: 43 ppm

Role of High Seed-Zn on Wheat Seedling Development in Pakistan

Picture: A. Rashid et al. 2017

Seed-Nickel

Effect of Ni Concentrations in Barley

Grain on Grain Viability/Germination

Welch, 1999, In: Mineral Nutrition of Crops. Fundemental Mechanisms and Implictions, FoodProducts Press)

Barley seeds

containing

negligible Ni failed

to germinate

adequately

Role of seed Ni on growth of soybean plants with and without external Ni applications

Kutman et al., 2014, Plant and Soil,

Effect of soil and foliar Mg treatments on seed vitality and vigour

Low Mg Adequate Mg

Ceylan et al., 2016, Plant and Soil

Low Mg Adequate Mg

Wheat Grains from plants with low and adequate MgSO4 treatment

Ceylan et al. 2016, Plant Soil

Wheat Grains under Different MgSO4 Treatments

Seeds from Mg-Adequate plants

Seeds from low Mg plants

Seeds from low Mg plants; but treated

foliarly with MgSO4

Ceylan et al. 2016, Plant Soil

Seeds with Low Mg

Seeds with Low Mg+Foliar MgSO4

Seeds with Adequate Mg

Ceylan et al., 2016, Plant Soil

Grain Mg Concentrationand Human Health

Mg deficiency: A growing nutritional problem in

human populationsAbout two thirds of the world’s population do not consume the daily

recommended amounts of magnesium (Rosanoff, 2013). There is also a

significant decline in Mg concentrations of cereal grains, mainly due to

dilution as a result of particular increases in grain yield in the past 50-60

years.

Too much Ca intake is also involved in alterations in Mg balance of body,

leading to impairment in Mg nutrition (Cakmak, 2015; Rosanof et al. 2016;

Crop and Pasture Science).

Low Mg in body might be responsible for sudden cardiac death, muscle

dysfunction, immunodeficiency, stroke etc (Rude and Gruber 2004; Nielsen,

2015).

Rosanoff, 2013; http://www.ancient-minerals.com/magnesium-deficiency

RDA: Recommended Dietary Allowance

MgSO4 SupplyGrain Mg

ConcentrationGrain Mg Content

mg kg-1 mg plant-1

Low 607 a 11.3 a

Low + Foliar Mg 790 b 22.3 a

Adequate 1426 c 50.7c

Grain concentration and content (total uptake)of bread wheat plants grown with i) low (50 μM), ii)low + foliar-Mg(50 μM + 4% MgSO4·7H2O) or iii) adequate (500 μM) Mg undergreenhouse conditions

Ceylan et al., 2016, Plant Soil

Picture: M. Grace

Plant Mineral Nutrition

to Fight Against

Hidden Hunger

• 5.9 million children under the age of 5

died in 2015. About 45% of all child

deaths are linked to malnutrition

• Hidden Hunger is the major form of

malnutrition

Media Centre: January, 2016

Iodine (I) deficiency represents a particular micronutrient deficiency in human populations occurring both in well-developed and developing countries. It is a serious health threat and affecting around 2 billion people (WHO, 2007).

Very low concentration of iodine in agricultural soils and cereal-based foods is widely believed as the major reason for iodine deficiency in humans, especially in developing world.

Europe has been shown as the region with the highest percentage of iodine deficiency incidence in human populations (Zimmermann and Andersson, 2011).

Iodine (I) deficiency

Iodine Deficiency in School Children

Based on urinary iodine data collected from the school children it has been estimated that about 1/3 of school children has insufficient iodine intake in the world (De Benosit et al, 2007; Anderson et al., 2012).

Inadequate iodine intake is still a growing health concerntoday. This is due to a number of factors, includingconstraints in availability of iodized salts for all households,instability of iodine during storage or cooking, lack ofmonitoring of iodine content in iodized salts, foodmanufacturers not using iodized salt in processed foods orthe increasing attention to minimize the daily sodiumintake.

About 50 % of the human population living in rural areasof several developing countries do not use iodized salt (Ziaet al., 2015).

Iodine deficiency is associated with various health complications including endemic goiter, intellectual and mental impairments, growth retardation, and increased infant mortality (Zimmerman, 2009; Lazarus, 2015).

People with low iodine intake can become dull, listless and easily

get tired

Iodine Deficiency Disorders: GoitreIodine Deficiency Disorders: Goitre

Effectiveness of soil- and foliar-applied iodine fertilizers on grain iodine concentrations of wheat, rice and maize grown under field conditions in Turkey, India, Thailand, Brazil and Pakistan was studied.

In a short-term experiment, translocation of iodine from older into younger leaves was also studied.

Additionally, the distribution of iodine within cereal grains and stability of iodine in foods were investigated

Field experiments conducted to study effect of iodine fertilization on grain iodine

Cakmak et al, 2017, Plant and Soil

0

100

200

300

400

0 0.013 0.032 0.065 0.129

Gra

in io

din

e (

µg

kg-1

)

KIO3 spray rate (%)

Brazil

Changes in iodine concentration of brown rice depending on foliar KIO3 treatment of plants grown in Brazil

Collaboration with Federal University of University

Control Foliar iodine treatment

Iod

ine

(mg

kg-1

)

0

10

200

300

400

500

600

Brown rice

Polished rice

Iodine concentration in brown and polished rice with and without foliar iodine spray in rice in Turkey

Cakmak et al, 2017, Plant Soil

Wheat Maize Rice

Response of wheat, maize and rice to foliar spray of iodine

Zn Fe Iodine Se

Plant (mg kg-1) (mg kg-1)

Wheat Control 28 30 6 5

Wheat Cocktail 70 47 729 428

Rice Control 19 10 11 63

Rice Cocktail 27 10 84 199

Foliar

Treatment(µg kg-1) (µg kg-1)

Response of wheat and rice to cocktail spray of iodine, zinc, iron and selenium

Cakmak et al., 2017, in review

Iodine Biofortification of Rice

No I-Treatment

10 ug/kg

Iodinebifortified rice

Iodine Concentration Iodine Concentration

106 ug/kg

Brasil: one of the largest grain exporting

countries globally

Grain Quality?

"Focus on better food,

not only more food "

Obrigado….